MCMedia RSS Feed - High_Energy_Physics https://news.mcmedia.cam/feed/High_Energy_Physics MCMedia News RSS Feed - High_Energy_Physics specific feed https://news.mcmedia.cam/rss-info.html MCMedia RSS Generator v1.0 Sun, 08 Mar 2026 19:30:37 +0000 Measurements of differential charged-current cross sections on argon for electron neutrinos with final-state protons in MicroBooNE https://arxiv.org/abs/2511.17342 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2511.17342v2 Announce Type: replace Abstract: This work presents single-differential electron-neutrino charged-current cross sections on argon measured using the MicroBooNE detector at the Fermi National Accelerator Laboratory. The analysis uses data recorded when the Neutrinos at the Main Injector beam was operating in both neutrino and antineutrino modes, with exposures of $2 \times 10^{20}$ and $5 \times 10^{20}$ protons on target, respectively. A selection algorithm targeting electron-neutrino charged-current interactions with at least one proton, one electron, and no pions in the final topology is used to measure differential cross sections as a function of outgoing electron energy, total visible energy, and opening angle between the electron and the most energetic proton. The interaction rate as a function of proton multiplicity is also reported. The total cross section is measured as [4.1 $\pm$ 0.3 (stat.) $\pm$ 1.1 (syst.)]$ $$\times 10^{-39} \mathrm{cm}^{2}/ \mathrm{nucleon}$. The unfolded cross-section measurements are compared to predictions from neutrino event generators commonly employed in the field. Good agreement is seen across all variables within uncertainties. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Measurement of the $e^+e^-\to\pi^+\pi^-\pi^0$ cross section in the energy region from 0.56 to 1.1 GeV with the SND detector https://arxiv.org/abs/2603.01635 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.01635v2 Announce Type: replace Abstract: The precise measurement of the $e^+e^-\to\pi^+\pi^-\pi^0$ cross section is performed in the center-of-mass energy range $E = 560$--1100 MeV using a data sample of 66 pb$^{-1}$ collected in the experiment with the SND detector at the VEPP-2000 $e^+e^-$ collider. The systematic uncertainty of the cross section measurement is 0.9\% at the maximum of the $\omega$ resonance and 1.2\% at the maximum of the $\phi$ resonance. The leading-order hadronic contribution to the muon magnetic anomaly calculated using the $e^+e^-\to\pi^+\pi^-\pi^0$ cross section measured by SND from 0.62 to 1.975 GeV is $(45.95\pm0.06\pm 0.46)\times 10^{-10}$. From the fit to the cross section data with the vector meson dominance model, the parameters of the $\omega$, $\rho$, and $\phi$ resonances are obtained. The obtained values of ${\cal B}(\omega\to e^+e^-) {\cal B}(\omega\to 3\pi)$, mass and width of the $\omega$ meson, and ${\cal B}(\rho\to 3\pi)$ have accuracy better than the current world average values. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Current status of the light neutralino thermal dark matter in the phenomenological MSSM https://arxiv.org/abs/2402.07991 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2402.07991v2 Announce Type: replace-cross Abstract: In a previous publication, we studied the parameter space of the phenomenological Minimal Supersymmetric Standard Model (pMSSM) with a light neutralino thermal dark matter ($M_{\tilde{\chi}_1^0} \leq M_h/2$) and observed that the recent results from the dark matter and collider experiments put strong constraints on this scenario. In this work, we present in detail the arguments behind the robustness of this result against scanning over the large number of parameters in pMSSM. The Run-3 of LHC will be crucial in probing the surviving regions of the parameter space. We further investigate the impact of light staus on our parameter space and also provide benchmarks which can be interesting for Run-3 of LHC. We analyse these benchmarks at the LHC using the machine learning framework of \texttt{XGBOOST}. Finally, we also discuss the effect of non-standard cosmology on the parameter space. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Long-lived Light Mediators in a Higgs Portal Model at the FCC-ee https://arxiv.org/abs/2503.08780 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2503.08780v2 Announce Type: replace-cross Abstract: In the search for beyond the Standard Model (SM) physics, long-lived particles (LLPs) have emerged as potential candidates and are being explored in various ongoing experiments. Future lepton colliders, such as the FCC-ee, shall provide an excellent opportunity to probe LLPs, owing to their clean environment and improved particle identification. This study investigates the potential of the proposed \textbf{I}nnovative \textbf{D}etector for an \textbf{E}lectron-Positron \textbf{A}ccelerator (IDEA) detector at FCC-ee in the detection of LLPs produced from $B$-meson and Higgs boson decays. We explore benchmark scenarios for different final states resulting from LLP decays, including a detailed analysis of the SM long-lived hadronic background. Additionally, we propose dedicated LLP detectors with different configurations, dimensions, and locations with respect to the IDEA detector. DELIGHT B, originally proposed as a dedicated LLP detector for the FCC-hh, stands out as the detector with the maximum efficiency for detecting LLPs produced at FCC-ee. We find that cylindrical detector configurations, if feasible to construct around the IDEA detector, would also enhance sensitivity for LLPs mostly decaying outside it. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Iterative HOMER with uncertainties https://arxiv.org/abs/2509.03592 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2509.03592v2 Announce Type: replace-cross Abstract: We present iHOMER, an iterative version of the HOMER method to extract Lund fragmentation functions from experimental data. Through iterations, we address the information gap between latent and observable phase spaces and systematically remove bias. To quantify uncertainties on the inferred weights, we use a combination of Bayesian neural networks and uncertainty-aware regression. We find that the combination of iterations and uncertainty quantification produces well-calibrated weights that accurately reproduce the data distribution. A parametric closure test shows that the iteratively learned fragmentation function is compatible with the true fragmentation function. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) The BUTTON-30 detector at Boulby https://arxiv.org/abs/2510.13173 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2510.13173v5 Announce Type: replace-cross Abstract: The BUTTON-30 detector is a 30-tonne technology demonstrator designed to evaluate the potential of hybrid event detection, simultaneously exploiting both Cherenkov and scintillation light to detect particles produced in neutrino interactions. The detector is installed at a depth of 1.1 km in the Boulby Underground Laboratory allowing to test the performance of this new technology underground in a low background environment. This paper describes the design and construction of the experiment. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Higher-Spin and Higher-Point Constraints on Stringy Amplitudes https://arxiv.org/abs/2603.04485 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04485v1 Announce Type: new Abstract: We employ multiparticle factorization to constrain deformations of tree-level open string amplitudes. Assuming minimal degeneracy among intermediate states of the same spin up through the second excited level, we find that the Regge intercept among all amplitudes of the Koba-Nielsen type can be uniquely fixed using seven-point factorization, precisely matching the bosonic string. Moreover, we produce novel constraints on deformations of the worldsheet integrand. We then turn to deformations of superstrings, with massless external states and arbitrary spectral degeneracy, using soft kinematics. Accounting for the infinite tower of higher-spin resonances, we obtain novel multipositivity bounds to leading and subleading order in the large-level limit. We apply these bounds to the simplest factorizable satellite deformation in the family of amplitudes found by Gross, showing that any deformation of four-point string amplitudes of this type is forbidden by unitarity. Our results reinforce the folklore that the higher-spin tower of string excitations is dramatically more rigid than any finite number of species. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Nonabelian Lattice Weak Gravity Conjecture and Monopole Confinement https://arxiv.org/abs/2603.04494 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04494v1 Announce Type: new Abstract: Within the known landscape of quantum gravity, most theories satisfy the Lattice Weak Gravity Conjecture (LWGC), which requires a superextremal particle at every site in the electric charge lattice $\Gamma$. However, counterexamples to the LWGC exist, and it was recently hypothesized that such counterexamples necessarily feature fractionally charged confined monopoles. In this work, we verify this hypothesis in toroidal orbifold compactifications of the heterotic string, which notably feature LWGC violation in both the abelian and nonabelian gauge sectors. In all the cases we consider, there exists a discrete subgroup of the center of the gauge group $K \subseteq Z(G)$ such that superextremal particles exist at every site in the charge lattice of the quotient group $G/K$, while (confined) monopoles exist at all sites in the magnetic charge lattice of $G/K$. This suggests that LWGC violation cannot occur for gauge groups with trivial centers, and more generally the degree of LWGC violation in a nonabelian gauge theory is bounded in terms of the maximal order of the center. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) From BPS geodesics to mode-driven dynamics in the scattering of multiple BPS vortices https://arxiv.org/abs/2603.04495 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04495v1 Announce Type: new Abstract: We analyze how the geodesic motion in the 3- and 4-vortex sectors of the Abelian-Higgs model at critical coupling is deformed by the excitation of a massive bound mode. We find that the geodesics corresponding to BPS solutions with enhanced symmetry remain unchanged, although the direction of the actual motion depends on the mode-generated force, i.e., a force arising from the change of the mode frequency along the geodesic. In a generic case, for example in head-on collisions between the axially symmetric 1- and 2-vortex or between two 2-vortices, the vortex trajectories can differ strongly from the BPS geodesic. This enhances the chaotic behavior in the formation of the final state. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Spin Chains from large-$N$ QCD at strong coupling https://arxiv.org/abs/2603.04506 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04506v1 Announce Type: new Abstract: We study the strong coupling expansion of large $N$ QCD in various dimensions, reformulating the Kogut-Susskind Hamiltonian on a square lattice in terms of (constrained) one dimensional spin chain models. We study the integrability properties of the spin chain obtained this way: there is large class of integrable subsectors, but we show that the full spin chain is not integrable, at least when viewed from a description based on Bethe ansatz. We demonstrate that the spin chains no longer possess integrability due to the constraints arising from the zigzag symmetry of the confining strings. The spin chain description properly estimates the roughening transition point by extrapolating the first-order analytical results based on integrability of some subsectors. The generalization to higher dimensions are also considered, where we also find the small subsectors without the zigzag constraints to be integrable. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Regge trajectories from the adjoint sector of Matrix Quantum Mechanics https://arxiv.org/abs/2603.04522 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04522v1 Announce Type: new Abstract: We reexamine the large $N$ limit of SU$(N)$ symmetric quantum mechanics of a Hermitian matrix whose singlet sector is well known to be exactly solvable via free fermions. When the Fermi level approaches a maximum of the potential, there is critical behavior corresponding to string theory in two dimensions. We uncover new phenomena in the adjoint sector by solving the Marchesini-Onofri equation both numerically and analytically using semiclassical approximations: at criticality, the spectrum is governed by Regge trajectories with energy eigenvalues growing according to $\Delta^2 \sim n/ \alpha'$. In the dual 2D string theory, we interpret these states as oscillatory excitations of a ``short'' folded open string. Up to sub-leading corrections, this Regge behavior is essentially universal and is insensitive to the particular potential we choose to approach criticality. Slightly away from criticality, the highly excited states transition into ``long strings'' that extend far into the Liouville direction. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) A smooth road to bumpy horizons: shaping black holes with non-linear sigma models, from supergravity to higher dimensions https://arxiv.org/abs/2603.04611 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04611v1 Announce Type: new Abstract: We construct new families of solutions for General Relativity coupled to a general class of non-linear sigma models, some of which can be embedded in supergravity. The solutions include neutral, charged and magnetized black holes with bumpy horizons, bumpy stars, and anisotropic cosmologies in $d\geq 4$ dimensions, as well as black strings and black $p$-branes. We also present a family of time-dependent solutions in $2+1$-dimensions. The construction relies on a set of first-order Bogomol'nyi-Prasad-Sommerfield relations for the coset scalars, that were recently exploited for the construction of bumpy black holes on the non-linear sigma model with homogenous target $SU(2)/U(1)$ in 2601.22914 [hep-th]. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Holographic QCD and quarkonium melting: Finite temperature, density, and external field effects in self-consistent dynamical models https://arxiv.org/abs/2603.04725 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04725v1 Announce Type: new Abstract: This MSc dissertation is based on the papers arXiv:2502.12694 and arXiv:2408.14813. The AdS/CFT correspondence provides a powerful framework for modeling strongly coupled gauge theories and, as a consequence, investigating non-perturbative phenomena in QCD. In this work, following an overview of the ideas that encapsulate the AdS/CFT correspondence, we present a self-consistent dynamical holographic QCD model within the Einstein-Maxwell-dilaton framework, derived from the coupled field equations, to study the mass spectra and melting behavior of heavy and exotic mesons at finite temperature and density. Finite temperature analyses reveal a confinement-deconfinement transition and sequential quarkonia melting. At finite density, an increase in chemical potential accelerates meson melting, with spectral functions evolving smoothly across the phase transition line. Finally, using a nonlinear Einstein-Born-Infeld-dilaton model, magnetic field effects demonstrate a shift from inverse magnetic catalysis to magnetic catalysis, highlighting the impact of spatial anisotropy on quarkonium stability. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) $N^{3/2}$ Scaling from $3d$ $\mathcal{N}=2$ Dualities: an Alternative Approach to Chiral Quivers https://arxiv.org/abs/2603.04849 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04849v1 Announce Type: new Abstract: We investigate families of 3d $\mathcal{N}=2$ chiral quiver gauge theories conjectured to be dual to M2-branes probing toric SE$_7$ singularities. Geometrically, these families correspond to toric diagrams without internal points. At the field theory level, the models are constructed via an un-higgsing procedure applied to non-chiral quivers. While the moduli space of these theories was shown to match M-theory expectations, determining the $N^{3/2}$ scaling of the free energy remained an open problem for over a decade, with positive results emerging only very recently. In this work, we address this challenge by reformulating the three-sphere partition function as a hyperbolic hypergeometric integral. Using exact integral identities, we show that the free energy reduces precisely to that of non-chiral quivers with chiral flavors, for which the $N^{3/2}$ scaling is already established. Physically, this mathematical identity corresponds to the equivalence of three-sphere partition functions under a generalization of Giveon-Kutasov duality to chiral quivers. Our results thus provide a large $N$ duality between the chiral quivers and non-chiral quivers with chiral flavors, confirming the $N^{3/2}$ scaling for the chiral quivers under study. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Parameter compression in the flux landscape https://arxiv.org/abs/2603.04941 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04941v1 Announce Type: new Abstract: We present a data-driven investigation of the exhaustive ensemble of no-scale type IIB flux vacua constructed in \cite{Chauhan:2025rdj}. Using a combination of linear and non-linear dimensionality-reduction techniques, we analyse both flux and moduli spaces and demonstrate that the effective dimensionality of the underlying 12-dimensional flux space is substantially reduced. A central component of our study is a physics-informed autoencoder, which provides a non-linear compression of the flux and moduli data into a low-dimensional latent space. The learned latent representation organises vacua according to desired features and, in particular, isolates distinguished regions associated with small values of the flux superpotential $|W_0|$, revealing non-trivial correlations that are not captured by linear methods. In parallel, we apply tools from topological data analysis, specifically persistent homology, to probe the global structure of the vacuum distribution. This allows us to identify robust, long-lived topological features in both moduli and flux subspaces. This work is a necessary step for developing foundation models in string phenomenology. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Gravitational instantons from closed superstring field theory https://arxiv.org/abs/2603.04953 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04953v1 Announce Type: new Abstract: We test exact marginality of the deformation describing the resolution of a $\mathbb{Z}_2$ orbifold by analyzing the closed superstring equations of motion to third order in the size, including $\alpha'$ corrections. We find that the third order correction is unobstructed for all deformation moduli. We are also able to reproduce the Eguchi-Hanson gravitational instanton up to the second order in the field theory limit with a suitable choice of moduli. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Introduction to holography https://arxiv.org/abs/2603.05186 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.05186v1 Announce Type: new Abstract: These are course notes for the 'Introduction to holography' Master level course at University of Cologne. The goal of the course is to give a pedogogical introduction to holography. Holography is a popular approach to quantum gravity, in which a theory of gravity can be described by a lower-dimensional boundary theory that itself has no gravity. The most concrete known example of a holographic model is the AdS/CFT correspondence, where the gravitational theory has a negative cosmological constant (the universe is asymptotically Anti-de Sitter) and the boundary theory is a conformal field theory. Symmetry plays a very important role in this duality. We therefore start the course with a review of Poincar\'e symmetry in quantum field theory, before moving on in the second chapter to conformal symmetry in conformally invariant quantum field theories or CFT's. Then we move to the basics of AdS physics in chapters 3 and 4, which will already reveal hints to the existence of a duality with CFT. After gathering the basic ingredients (CFT and AdS), in the second half of the course we are ready to formulate the AdS/CFT correspondence (chapter 5), including finite temperature AdS/CFT (chapter 6), which involves black holes and their thermodynamics in the gravitational theory (chapter 7). We end the course with an introduction to entanglement in AdS/CFT and the origin of statements that 'gravity emerges from entanglement' in holography. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Discrete \texorpdfstring{$\theta$}{theta} Projection: A Gauge-Protected Solution to the Strong CP Problem Without Axions https://arxiv.org/abs/2603.05195 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.05195v1 Announce Type: new Abstract: We address the strong CP problem: why the physical QCD angle theta-bar must be extraordinarily small given the stringent bounds on the neutron electric dipole moment. Peccei-Quinn axion models can relax theta-bar dynamically, but rely on an approximate global symmetry expected to be violated by quantum gravity and face severe astrophysical and cosmological constraints. We propose Discrete theta Projection, an axionless, gauge-protected resolution obtained by gauging a finite cyclic subgroup $Z_N $of the $2\pi$ shift symmetry of theta. Coupling QCD to a compact, local and gapped topological sector orbifolds the path integral, identifying theta values that differ by $2\pi/N$ and admitting only instanton sectors whose topological charge lies in $Z_N$. In the large four-volume limit the vacuum energy becomes the lower envelope of the orbifold images, so the theory dynamically selects the branch closest to the CP-symmetric point, enforcing $|\bar{\theta}| \le \pi/N$ without assuming any prior smallness. Because the discrete shift is gauged, continuous renormalization of theta is forbidden; the construction can be formulated via higher-form/two-group structure with integer-quantized couplings fixed by anomaly inflow, ensuring radiative and gravitational stability and satisfying mixed gauge-gravity consistency conditions. The framework predicts a neutron EDM suppressed by $1/N$, no axion signatures, no domain-wall/isocurvature issues, and lattice diagnostics: piecewise-analytic theta dependence with cusps at odd fractions of the reduced period and a global curvature scaling as $1/N^2$. We provide the EFT construction, a nonperturbative proof of vacuum projection, a full anomaly analysis, and UV embeddings (including discrete clockwork chains) that generate large effective N while preserving integrality and consistency throughout. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Gauge-string duality, monomial bases and graph determinants https://arxiv.org/abs/2603.05259 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.05259v1 Announce Type: new Abstract: Questions at the intersection of the AdS/CFT correspondence and quantum information theory motivate the study of projectors in sequences of subalgebras of finite-dimensional commutative associative semisimple algebras $\mathcal{A}$, obtained by incrementally adjoining one generator at each step to produce a non-linear generating set for $\mathcal{A}$. We define degeneracy graphs, which are finite layered tree graphs whose nodes represent projectors in the successive subalgebras. Using combinatorial properties of the degeneracy graph, we give a simple formula for constructing a linear basis of $\mathcal{A}$ in terms of monomials in the generators.The nodes can be labelled by formal variables corresponding to the eigenvalues of the generators added at each layer. We prove that the construction is compatible with the required counting of projectors in $\mathcal{A}$, and give explicit constructions of the projectors in terms of the monomials, in the cases of one- and two-layer degeneracy graphs with arbitrary numbers of nodes. More generally, we provide extensive computational evidence for the invertibility of the matrix relating the proposed monomial basis to the projector basis, by evaluating its determinant. In the 1-layer case, this is a Vandermonde determinant. A simple formula for the non-vanishing determinant in the general layer case is conjectured and supported by the computational data. The construction is illustrated with examples including centres of symmetric group algebras and maximally commuting subalgebras generated by JucysMurphy elements. We outline applications of the monomial basis to algorithms for constructing matrix units in non-commutative semisimple algebras, with relevance to orthogonal bases of multi-matrix gauge-invariant operators and to quantum information theory. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) 7D (non-)susy vacua & DWs from dynamical open strings https://arxiv.org/abs/2603.05470 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.05470v1 Announce Type: new Abstract: Warped compactifications of massive type IIA supergravity on a 3-sphere with spacetime-filling O6/D6 sources are known to admit a half-maximal gauged supergravity description in 7D. We study the effect of introducing open string degrees of freedom (scalars and fluxes) in such dimensional reductions, associated with the spacetime-filling sources. From the 7D supergravity point of view, this can be realized by coupling the gravity multiplet with extra vector multiplets and adding new components to the embedding tensor describing the gauging. The scalar potential of the underlying theory exhibits novel AdS7 vacuum solutions, with and without supersymmetry. Finally, we explore the net of domain wall solutions interpolating between the different pairs of vacua, and present analytical as well as numerical solutions. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Scattering amplitudes in dimensionless quadratic gravity coupled to QED https://arxiv.org/abs/2603.05476 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.05476v1 Announce Type: new Abstract: We study ultra-Planckian $2\to2$ scattering in an Abelian gauge theory coupled to agravity, the scale-free and renormalizable realization of quadratic quantum gravity. Focusing on charged fermions and scalars interacting with the photon and the higher-derivative graviton, we present compact analytic expressions for the unpolarized squared matrix elements for a broad set of tree-level processes, including photon--photon, fermion--fermion, fermion--photon, scalar--fermion, scalar--photon, scalar--scalar, and annihilation channels. In contrast to purely graviton-mediated analyses, we retain systematically the photon--graviton interference contributions and verify explicitly the independence of the results on the gravitational gauge-fixing parameter. The amplitudes display characteristic forward/backward enhancements associated with small momentum transfer, amplified by the $1/p^{4}$ graviton propagator, while their high-energy scaling reflects the underlying dimensionless gravitational couplings. Moreover, for all channels analyzed the corresponding differential cross sections exhibit the universal ultra-Planckian scaling $d\sigma/d\Omega \propto 1/s$, where $s$ is the Mandelstam invariant (the squared center-of-momentum energy). Our results furnish a unified amplitude-level description of how higher-derivative gravity reshapes familiar QED scattering at ultra-Planckian energies and provide analytic building blocks for further studies of IR definitions and UV consistency in agravity with matter. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) The MexNICA Collaboration in the MPD-NICA Experiment at JINR: Experimental and Theoretical Achievements https://arxiv.org/abs/2603.04468 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04468v1 Announce Type: cross Abstract: The MexNICA Collaboration coordinates the activities of Mexican scientists, engineers, postdoctoral fellows and students in the Multi-Purpose Detector experiment at the Nuclotron-based Ion Collider fAcility of the Joint Institute for Nuclear Research in Dubna, Russia. Established in 2016, the collaboration brings together five Mexican institutions whose contributions span detector development as well phenomenological and theoretical studies, including modeling by means of Monte Carlo simulations. This work summarizes the main achievements of MexNICA, consisting of the development of the miniBeBe trigger detector as well of results of phenomenological investigations of the baryon-rich region in the QCD phase diagram accessible at NICA energies, and theoretical advances based on lattice QCD and effective models. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) 50 Years of SUSY and SUGRA, circa 1974-2024, and Future Prospects https://arxiv.org/abs/2603.04664 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04664v1 Announce Type: cross Abstract: The development in the early seventies of supersymmetry, in the mid-seventies of gauge supersymmetry and supergravity, and in the early eighties of gravity mediated breaking of supersymmetry and of supergravity grand unification have led to remarkable progress in the pursuit of unification of fundamental interactions of particle physics. They have also led to the intertwining of particle physics, cosmology, and strings. Since supersymmetry and supergravity are manifest in the low energy limit of superstring below the Planck scale, experimental test of them are of interest regarding the validity of the superstring itself. For that reason, over the past decades, after the advent of supersymmetry and SUGRA models, there have been sustained experimental searches for supersymmetry at colliders, in precision experiments, and in astrophysical and cosmological data. The SUSY and SUGRA models have also had deep impact on theories related to inflation, dark matter, and dark energy. The purpose of this article is to provide a view from the bridge of these developments over the past fifty years circa 1974-2024. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) The effect of charm quark on the QCD chiral phase diagram https://arxiv.org/abs/2603.04728 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04728v1 Announce Type: cross Abstract: We study the influence of charm quark dynamics on the chiral phase structure of Quantum Chromodynamics (QCD) using the recently developed miniDSE scheme of the Dyson-Schwinger equations. By calculating the quark propagator in $2+1$ and $2+1+1$ flavor QCD, we quantify the impact of including the charm quark as a dynamical degree of freedom on the QCD phase diagram. Our results show that the charm quark induces a moderate but noticeable shift to lower chemical potential in the location of the critical endpoint (CEP) by approximately 2-3%. The result in this work indicates that the heavy-flavor dynamics can subtly influence the QCD phase structure and should be taken into account in particular for searching the CEP of QCD. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Magnetic moments of strange hidden-bottom pentaquarks and the role of spin flavor correlations https://arxiv.org/abs/2603.04911 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04911v1 Announce Type: cross Abstract: We investigate the magnetic moments of strange hidden bottom pentaquark states within the constituent quark model considering molecular and compact configurations. The system with quark content qqqbb is analyzed in three scenarios a baryon meson molecular configuration bq1bq2q3 a diquark diquark antiquark configuration bq1q2q3b and a diquark triquark configuration bq1bq2q3. The negative parity states with are studied for strangeness. We find that for the dominant spin couplings and maximally aligned configurations the diquark diquark antiquark qqqbb and diquark triquark bqqqb descriptions yield identical or numerically very close magnetic moments indicating that in the hidden bottom sector the magnetic properties are governed primarily by the global spin flavor structure rather than clustering details. A systematic suppression with increasing strangeness and a clear spin hierarchy are observed in all configurations. Due to the large bottom quark mass, heavy quark contributions are strongly suppressed, making the magnetic moments primarily sensitive to light strange spin correlations. These results provide theoretical benchmarks for future experimental studies of exotic multiquark states. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Renormalisation of Chiral Gauge Theories with Non-Anticommuting $\gamma_5$ at the Multi-Loop Level https://arxiv.org/abs/2603.05059 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.05059v1 Announce Type: cross Abstract: This thesis presents a comprehensive study of the renormalisation of chiral gauge theories in dimensional regularisation (DReg) at the multi-loop level. We employ the mathematically consistent Breitenlohner-Maison/`t~Hooft-Veltman (BMHV) scheme with non-anticommuting $\gamma_5$, whose modified algebraic relations induce a spurious violation of gauge and BRST invariance. A central focus is the systematic restoration of the broken symmetry, for which we provide a transparent and fully algorithmic procedure based on the quantum action principle. A major achievement of this work is the complete 4-loop renormalisation of an Abelian chiral gauge theory -- the highest-order application of the BMHV scheme to date. This calculation is made possible by an automated, high-performance computational framework incorporating several optimised algorithms. Our results demonstrate that a rigorous, self-consistent treatment of $\gamma_5$ is feasible even at very high loop orders. We further analyse dimensional ambiguities and evanescent details corresponding to different implementations of the regularisation, and identify practically efficient prescriptions for $D$-dimensional fermions and gauge interactions. Building on these insights, we present the complete 1-loop renormalisation of the full Standard Model (SM) in the BMHV scheme, providing a first step towards a fully self-consistent multi-loop renormalisation of the SM and establishing a solid foundation for future high-precision electroweak phenomenology. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Constraints on new physics from decays of polarized $\Lambda_b^0$ baryons at the FCC-ee https://arxiv.org/abs/2510.02225 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2510.02225v2 Announce Type: replace Abstract: The $Z^0$ bosons produced in electron-positron collisions at the potential Future Circular Collider (FCC-ee) provide unique opportunities for flavour physics. The non-zero polarization of \Lb baryons produced in $Z^0$ decays enables access to a much larger set of observables than at the LHC, where the $\Lambda_b^0$ baryons are produced unpolarized. This paper presents a toy angular analysis of $\Lambda_b^0\to \Lambda(\to p\pi^-)\mu^+\mu^-$ decays using simulation samples of collisions at the FCC-ee reconstructed using the IDEA detector concept and assuming a dataset of $6\times 10^{12}$ $Z^0$ bosons. While the statistical sensitivity achieved for individual angular observables is not expected to significantly exceed that from the LHCb Upgrade II experiment, the addition of the polarized observables leads to a significant improvement of the knowledge on the Wilson coefficients $C_{9^{(\prime)}}$ and $C_{10^{(\prime)}}$. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Connecting Flavor and Baryon Asymmetry via Leptogenesis in Effective Froggatt-Nielsen Theory https://arxiv.org/abs/2603.05372 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.05372v1 Announce Type: cross Abstract: We investigate the hierarchical flavor structure of the Standard Model in a Froggatt-Nielsen (FN) framework, where the spontaneous breaking of a $U(1)_{\rm FN}$ symmetry by a complex flavon field generates fermion masses and mixing patterns through higher-dimensional operators. Extending the setup with three right-handed neutrinos (RHNs), light neutrino masses arise via the Type-I seesaw mechanism. Allowing complex FN coefficients enables a consistent description of the CKM and PMNS matrices while inducing CP-violating signatures in meson decays. Building on our previous work, where the lightest RHN acts as a viable dark matter (DM) candidate produced through freeze-in or freeze-out mechanisms, we investigate the origin of the baryon asymmetry of the Universe. The heavier RHNs generate a lepton asymmetry through out-of-equilibrium decays, including both Standard Model channels and additional flavon-induced processes in which the flavon appears as an intermediate or final-state particle. We compute the corresponding one-loop CP asymmetries and incorporate these effects in the Boltzmann equations. We show that although freeze-in and freeze-out DM production occur in two qualitatively distinct regions of the FN symmetry-breaking scale $v_\phi$, successful thermal leptogenesis can be achieved in both regimes. In the large-$v_\phi$ (freeze-in-compatible) region the results approach the standard leptogenesis limit, while in the freeze-out-compatible region the lower value of $v_\phi$ implies lighter RHNs, requiring resonant enhancement. This tightly constrained framework, in which $v_\phi$ simultaneously controls RHN masses and the interaction strengths of the flavon and DM sectors, provides a predictive and unified description of flavor hierarchies, neutrino masses, CP violation, dark matter, and baryogenesis within a single effective theory. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Exploring $T_{\Upsilon\Upsilon}$ tetraquark candidates in a coupled-channels formalism https://arxiv.org/abs/2603.05311 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.05311v1 Announce Type: cross Abstract: We investigate the spectrum of $T_{\Upsilon\Upsilon}$ tetraquark candidates within a coupled-channels framework. The analysis includes all $L\leq2$ combinations of $\Upsilon(1S)$, $\Upsilon(2S)$, $\eta_b(1S)$, and $\eta_b(2S)$ in the $J^P = 0^\pm, 1^\pm, 2^\pm$ sectors. The meson-meson interaction is derived from an underlying constituent quark model through the resonating group method, and the properties of the states are obtained from poles of the scattering matrix. We find a rich spectrum of resonant, and virtual, states distributed between the $\eta_b(1S)\eta_b(1S)$ and $\Upsilon(2S)\Upsilon(2S)$ thresholds. The pattern of poles exhibits approximate heavy-quark spin symmetry multiplets. Several states are dominated by a single channel and can be associated with threshold-driven structures, while higher-mass resonances show sizable mixing among channels involving radially excited bottomonia. The predicted widths range from tens to several hundred MeV. Branching ratios indicate that many states couple predominantly to final states with at least one excited bottomonium, whereas only a subset of the spectrum is expected to be visible in the $\eta_b(1S)\eta_b(1S)$, $\eta_b(1S)\Upsilon(1S)$ and $\Upsilon(1S)\Upsilon(1S)$ channels. These results provide quantitative guidance for experimental searches of fully heavy tetraquarks and offer a test of coupled-channel dynamics and heavy-quark spin symmetry in the $bb\bar b\bar b$ sector. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Axial-vector neutral-current measurements in coherent elastic neutrino-nucleus scattering experiments https://arxiv.org/abs/2603.05281 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.05281v1 Announce Type: cross Abstract: Coherent elastic neutrino-nucleus scattering (CE$\nu$NS) is predominantly governed by vector neutral-current interactions, with subleading contributions arising from the axial current in nuclei with non-zero ground-state spin. Experimentally, the extraction of axial-current contributions has been so far of little interest, mainly because of the challenges its measurement entail. In this work, we investigate the relative size of the vector and axial components for target materials currently employed by the neutrino and dark matter experimental communities. We identify fluorine-based compounds as the most promising targets for probing the axial-current event rate. Among them, octafluoropropane ($\text{C}_3\text{F}_8$) emerges as a particularly suitable candidate, given its widespread use in spin-dependent dark matter searches and its relevance for upcoming dedicated CE$\nu$NS experiments. Considering both pion decay-at-rest and reactor neutrino fluxes, we show that such measurements can allow an indirect determination of the axial coupling at the $\sim 10\%$ level, depending on flux uncertainties and detector thresholds. We further emphasize that measurements of the axial current will allow to probe spin-dependent new physics scenarios through CE$\nu$NS. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Muon collider experiments as electron/positron beam sources: case studies of new light-particle searches https://arxiv.org/abs/2603.05086 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.05086v1 Announce Type: cross Abstract: At muon colliders, muon decays naturally produce intense electrons and positrons with unique features, namely high energies, high repetition rates, and small intrinsic uncertainties, that are unavailable at existing accelerator facilities. We quantitatively study the feasibility of extracting such particles in two representative future muon collider designs, IMCC and $\mu$TRISTAN. Using Monte Carlo simulations with the corresponding design parameters, we study the spatial, angular, and energy distributions of decay electrons and positrons in the curved sections of the collider ring. We find that typical deflections of $0.1-10~\mathrm{mrad}$ can be achieved even for high-energy electrons carrying large energy fractions ($\simeq 0.6 - 1.0$) of the muon beam energy, with the ring bending magnets (or magnets providing an equivalent field) effectively serving as a pre-septum magnet, that partially deflects the beam before the main septum magnet, suggesting that the extraction scheme could be practically feasible. Exploiting the distinct beam properties of IMCC and $\mu$TRISTAN, we propose complementary search strategies, missing energy and momentum searches for dark matter at $\mu$TRISTAN and visible-decay searches for axion-like particles and light scalars at IMCC, which probe parameter space beyond the reach of current and other proposed experiments. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) On the robustness of the indirect determination of the width of the detected Higgs boson https://arxiv.org/abs/2603.05020 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.05020v1 Announce Type: cross Abstract: The indirect determination of the total width of the detected Higgs boson that is carried out by the experimental collaborations at the LHC relies on the assumption that the coupling modifiers for the on-shell and off-shell couplings are the same. However, physics beyond the Standard Model affecting the on-shell and off-shell regions differently could invalidate this assumption, so that the actual width of the detected Higgs boson could be larger than the bounds obtained under this assumption. Relaxing the assumption and investigating different types of extensions of the Standard Model, we analyse under which conditions a larger total width of the detected Higgs boson is compatible with all experimental and theoretical constraints. For the considered scenarios of scalar extensions with an additional state contributing as a resonance or at the loop level, we find that the indirect bounds obtained by ATLAS and CMS remain valid over large parts of the parameter space, with the exception of parameter regions where the additional particles have relatively small masses. We discuss the potential of experimental searches for new particles to further constrain such scenarios. Based on the existing experimental and theoretical constraints we conclude that relaxing the assumption of equal on-shell and off-shell coupling modifiers that is used in the experimental analyses at the LHC yields an upper bound on the total width of the detected Higgs boson in realistic extensions of the Standard Model that is only weakened by up to a factor of about two compared to the case where this assumption is valid. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Sensitivity of a closed dielectric haloscope to axion dark matter https://arxiv.org/abs/2603.05006 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.05006v1 Announce Type: cross Abstract: We present a method to determine the sensitivity of a closed dielectric haloscope to axion dark matter. Dielectric haloscopes aim to probe the theoretically well-motivated axion mass range of ~26 $\mathrm{\mu}$eV to ~500 $\mathrm{\mu}$eV by utilizing a stack of dielectric disks and a mirror to enhance the axion-photon conversion within an external magnetic field. Their conversion volume is nearly axion-mass independent, thereby favoring large-scale designs to increase sensitivity. The large volume causes simulations to be computationally expensive and time-consuming. This paper presents a simple model that can be used to determine the sensitivity of the experiment with minimal computational resources. The model is able to describe the electromagnetic response of a closed dielectric haloscope, accounting for realistic geometric imperfections, as well as the noise introduced by the receiver system. It is applied to data taken with a MAgnetized Disk and Mirror Axion Experiment (MADMAX) prototype within the 1.6 T Morpurgo magnet at CERN. This work underpins the first axion dark matter search using a dielectric haloscope and provides the foundation for future dark matter searches with MADMAX. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Covariant canonical-spinor amplitudes for partial wave analysis https://arxiv.org/abs/2603.04487 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04487v1 Announce Type: cross Abstract: We propose a covariant orbital-spin ($LS$) decomposed amplitude for the partial wave analysis using the massive spinor-helicity formalism. First we review the traditional-$LS$ method in the little group space and the Zemach tensor method in the double cover of the $\mathrm{SO}(3)$ space. To recover the $\mathrm{SO}(3,1)$ Lorentz covariance, several Lorentz covariant $LS$ tensors have been constructed in several different methods: covariant tensor, covariant projection tensor in pure-spin and general-spin schemes, but performing a intrinsic separation between $LS$ coupling while maintaining covariance is not obvious. We utilize the massive canonical-spinor variables to determine general three-point amplitudes, in which the spin-orbital decomposition is realized in single little group space by projecting little group indices of each particles into one, while the Lorentz covariance is ensured by the spinor form naturally. This covariant spinor method allows direct evaluation in any frame and a streamlined treatment of cascade decays within a single frame without additional alignment rotations in non-covariant treatment. As a benchmark, we implement the method in TF-PWA and analyze $\Lambda_c^+\to\Lambda\pi^+\pi^0$, finding consistent fit results across the helicity, traditional-$LS$, and canonical-spinor amplitudes. This validates the canonical-spinor amplitude as a practical tool for modern partial wave analyses of complex decay chains. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) A baryon-calibrated unified quark-diquark effective mass formalism for heavy multiquarks https://arxiv.org/abs/2603.04175 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04175v1 Announce Type: cross Abstract: We present a unified framework for heavy tetraquark and pentaquark systems within the quark-diquark effective mass formalism, extending its baryon-calibrated construction to multiquark states without introducing sector-dependent parameters. Intra-diquark color-spin correlations are encoded in effective diquark masses fixed from baryon spectroscopy, while the inter-cluster chromomagnetic scale, independently determined from vector-pseudoscalar meson splittings, is propagated unchanged to exotic configurations, ensuring residual one-gluon exchange dynamics only between composite color sources. Within this framework, we compute the complete spectra for both $\bar{\mathbf{3}}_c\otimes\mathbf{3}_c$ and $\mathbf{6}_c\otimes\bar{\mathbf{6}}_c$ configurations in tetraquarks, whereas the pentaquark analysis focuses on the dominant $\bar{\mathbf{3}}_c\otimes\bar{\mathbf{3}}_c\otimes\bar{\mathbf{3}}_c$ clustering. Heavy-quark spin symmetry and flavor-symmetry breaking across light, charm, and bottom sectors emerge naturally through the explicit $1/(m_{D_1}m_{D_2})$ scaling of the calibrated couplings. The resulting spectra exhibit a coherent dynamical hierarchy spanning baryons and multiquark states. Established exotic candidates are reproduced within hadronic uncertainties, while the unified calibration enables quantitative predictive control across flavor sectors. The framework thus provides a parameter-economical, systematically constrained baseline with unified dynamical consistency for heavy multiquark spectroscopy. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Matter Unification and Lepton Flavour Violation https://arxiv.org/abs/2603.02313 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.02313v1 Announce Type: cross Abstract: We explore the idea of quark-lepton unification at low energies. In particular, we discuss the minimal framework for matter unification at the multi-TeV scale, in which neutrino masses are necessarily generated via the inverse seesaw mechanism. To assess the testability of this theory for physics beyond the Standard Model, we analyze current experimental constraints and derive the corresponding lower bound on the symmetry breaking scale. We reexamine the impact of existing limits from lepton number violating meson decays, taking into account the freedom associated with unknown quark-lepton mixing angles. Furthermore, we study the correlation between bounds from meson decays and $\mu \to e$ conversion. We demonstrate that the upcoming $\mu \to e$ conversion experiment at Fermilab can play a crucial role in probing quark-lepton unification at the multi-TeV scale. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Gravitational Wave Peep Contributions to Background Signal Confusion Noise for LISA https://arxiv.org/abs/2507.19704 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2507.19704v2 Announce Type: replace Abstract: Two-body gravitational interactions will occasionally lead to a stellar-mass compact object entering a very highly eccentric orbit around a massive black hole at the center of a galaxy. Gravitational radiation damping will subsequently result in an extreme mass ratio inspiral. Much of the inspiral time of these events is spent with the compact object on a long-period orbit, with a brief burst of gravitational wave emission at periapsis firmly in the mHz band. Burst orbits have been previously modeled as parabolic, with a focus on extreme examples that could be detectable by space-based gravitational wave detectors. This work focuses on the recurring bursts called ``peeps". Peeps are not likely to be individually resolvable; however, it is also important to consider them as possible sources of signal confusion noise because they do generate a signal within the LISA band with every pericenter passage. To account for peeps, we must utilize estimates for EMRI capture parameters along with tracking the massive black hole population out to a redshift of 3 using the Illustris Project. Then, this population is combined with an EMRI formation rate to estimate the number of EMRI events per unit volume for LISA. In this study, we model four different assumptions for the gravitational wave background produced by these highly eccentric peeps. We find that with our two most likely backgrounds, the signal may result in a slight rise of the LISA noise floor (SNR $\sim 0.3-2.4$); however, in two more abundant cases, the background generated by these sources would be detectable on their own and likely obscure many potentially detectable sources (SNR $\sim77-145$). High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Probing Hawking Temperature Threshold via Quantum Depletion in Bose-Einstein Condensate https://arxiv.org/abs/2506.04597 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2506.04597v2 Announce Type: replace Abstract: We investigate the correlation between quantum depletion and Hawking temperature in a ringshaped Bose-Einstein condensate featuring an analog black hole-white hole horizon pair, using the Bogoliubov approach. The presence of horizons is found to enhance the quantum depletion compared to horizon-free configurations, indicating a correlation between depletion and horizon dynamics. Via tuning the Hawking temperature, we observe its effect on the depletion profile. Our results show that depletion increases with Hawking temperature, and beyond a certain threshold, backreaction effects emerge, challenging the validity of the Bogoliubov approximation. We identify a viable parameter regime where the system remains both theoretically controlled and experimentally accessible, offering insight into horizon-induced quantum fluctuations, with implications for future studies of backreaction. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Bayesian model selection of Primordial Black Holes and Dressed Primordial Black Holes with lensed Gravitational Waves https://arxiv.org/abs/2504.14980 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2504.14980v2 Announce Type: replace Abstract: If particle dark matter (DM) and primordial black holes (PBHs) coexist, PBHs will be surrounded by particle DM, forming celestial objects known as dressed PBHs (dPBHs). These structures suggest a scenario in which PBHs and DM can exist simultaneously. However, in the high-frequency regime, the gravitational lensing effect of bare PBHs is similar to that of dPBHs. Ground-based gravitational wave (GW) detectors are particularly sensitive to high-frequency GW signals. In this regime, the lensing effect of a point-mass lens with a mass in the range of $10^{-1} \sim 10^2 M_{\odot}$ becomes significant. In this work, we incorporate dPBH models with GW observations and employ Bayesian inference techniques to distinguish PBHs from dPBHs. Using the third-generation ground-based GW detectors, Einstein Telescope (ET) and Cosmic Explorer (CE), as examples, we demonstrate that these detectors can effectively differentiate the lensing effects of dPBHs from those of PBHs across a broad frequency range. Furthermore, we find that with a larger black hole (BH) mass inside the surrounding particle DM, ET and CE can distinguish these two lensed models with even greater precision. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Firewalls, black-hole thermodynamics, and singular solutions of the Tolman-Oppenheimer-Volkoff equation https://arxiv.org/abs/1511.07051 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:1511.07051v2 Announce Type: replace Abstract: We investigate thermodynamic equilibrium of a self-gravitating perfect fluid in a spherically symmetric system containing a black hole of mass M by means of the Tolman-Oppenheimer-Volkoff (TOV) equation. At r >> 2M its solutions describe a black-body radiation atmosphere with the Hawking temperature T_BH~1/(8 \pi M) that is increasingly blueshifted as r approaches 2M. However, there is no horizon at the Schwarzschild radius. Instead, the fluid becomes increasingly hot and dense there, piling up into a "firewall" with the peak temperatures and densities reaching Planck values somewhat below r = 2M. This firewall surrounds a negative point mass residing at r=0, the only singularity of the solution. The entropy of the firewall is comparable to the Bekenstein-Hawking entropy. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Canonical Quantisation of Bound and Unbound WQFT https://arxiv.org/abs/2603.05237 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.05237v1 Announce Type: cross Abstract: Using canonical quantisation, and eschewing the Schwinger-Keldysh path integral, we derive a version of the Worldline Quantum Field Theory (WQFT) formalism suitable for both scattering and bound configurations of the classical two-body problem. Focusing on a pair of charged particles interacting via a scalar field, we quantise Hamilton's equations both in flat space and around a non-zero background, perturbing in post-Lorentzian (PL) and self-force (SF) expansions respectively. Our quantisation procedure provides access to the Magnus series, and is perfectly suited for computing matrix elements of $\hat{N}(t,t_0)=- i \hbar \log\hat{U}(t,t_0)$, both with and without external scalar states, for finite time intervals (bound orbits) and infinite time intervals (scattering). Doing so, we provide a complete set of gauge-invariant matrix elements describing the 1SF scattering dynamics up to 3PL order, and corresponding matrix elements for bound orbits. We also demonstrate how $\hat{N}$-matrix elements encode physical observables, providing a unified operator-based framework for conservative and radiative dynamics of binary systems. The new WQFT formalism generalises naturally to both gravity and electromagnetism. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Crunching, Bouncing, and Cyclical Cosmologies from Dark Sector Interactions https://arxiv.org/abs/2603.02332 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.02332v1 Announce Type: cross Abstract: We present new mechanisms that produce either a future Big Crunch turnaround or a past non-singular bounce in flat FLRW cosmologies within general relativity at the background level, driven solely by non-gravitational interactions between dark matter (DM) and dark energy (DE). We study phenomenological interacting dark energy (IDE) models based on linear kernels of the form $Q = 3H(\delta_{\rm dm}\rho_{\rm dm} + \delta_{\rm de}\rho_{\rm de})$, focusing on parameter regimes with strong energy transfer from dark energy to dark matter. In this strong interacting regime, the interaction does not vanish when one component crosses zero density, allowing one of the dark-sector densities to become negative. The resulting sign changes can violate the energy conditions required for cosmological turnarounds in a flat universe, thereby enabling either (i) a maximum scale factor followed by recollapse into a big crunch, or (ii) a minimum non-zero scale factor corresponding to a bounce. We derive analytic conditions for these turnarounds and obtain closed-form expressions for the associated maximum or minimum scale factor. We also show that, in a closed universe, a special case of the same IDE framework can be tuned to yield a cyclic scenario. Although these strong interaction scenarios are unlikely to describe the observed Universe, they provide a concrete demonstration that exotic cosmological behaviour can arise naturally in underexplored regions of the parameter space of familiar IDE models. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Accretion Disk Perturbations and Their Effects on Kerr Black Hole Superradiance and Gravitational Atom Evolution https://arxiv.org/abs/2603.05182 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.05182v1 Announce Type: new Abstract: Kerr black hole (BH) superradiance can form gravitational atoms and produce characteristic gravitational-wave signals, providing a probe of ultralight bosons and dark matter. In realistic systems, accretion-disk gravity can shift energy levels and mix states, modifying the effective superradiant growth. We model the disk as a weak external perturbation via a multipole expansion and derive an effective three-level Hamiltonian for the $n=2$ subspace $\{\ket{211},\ket{210},\ket{21-1}\}$ in the weak-coupling regime. The leading disk effect is the quadrupolar ($\ell_d=2$) tidal field, whose symmetries fix the selection rules: axisymmetry gives only diagonal shifts, equatorial nonaxisymmetry activates $\Delta m=\pm2$ mixing ($\ket{211}\leftrightarrow\ket{21-1}$), and breaking equatorial reflection opens $\Delta m=\pm1$ couplings involving $\ket{210}$. As illustrations, a transient equatorial $m=2$ spiral wave drives the resulting two-level system and can suppress or quench superradiance by populating a decaying mode, while a quasi-static warp produces full three-level mixing and can generate narrow ``growth gaps'' near accidental near-degeneracies, with the same static reshuffling also allowing enhancement when weight shifts toward the growing mode. These findings demonstrate that accretion disk perturbations are a crucial environmental factor in determining the dynamics of BH superradiance and the evolution of boson clouds, thereby providing a more reliable theoretical basis for assessing the detectability of ultralight bosons in realistic astrophysical settings. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) New Improved Schwarzschild Black Hole and Its Thermodynamics and Topological Classification https://arxiv.org/abs/2603.05130 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.05130v1 Announce Type: new Abstract: We construct a renormalization-group improved Schwarzschild-like black hole geometry using the exact new scheme running for the Newton coupling. The scale identification is implemented via a standard interpolating proper-distance function that smoothly connects the ultraviolet and infrared regimes. We present the resulting coordinate-dependent coupling and the improved metric function, analyzing its asymptotic expansions. The large-distance limit is shown to recover the classical Schwarzschild solution, while the short-distance behavior exhibits a regular de Sitter-like core, demonstrating the regularization of the central singularity. We also analyze the thermodynamic properties of the solution, showing that quantum corrections significantly modify the small-radius behavior, leading to a remnant configuration and a nontrivial phase structure. Finally, we perform a topological classification of the thermodynamic phase space and demonstrate that asymptotically safe effects shift the critical point while preserving the global topological number of the Schwarzschild solution. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Double-sphere enhanced optomechanical spectroscopy constrains symmetron dark energy https://arxiv.org/abs/2603.05090 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.05090v1 Announce Type: new Abstract: Screened scalar fields such as the symmetron provide a viable description of dark energy yet their laboratory detection remains challenging. We propose an optomechanical scheme to constrain symmetron interactions using two optically levitated nanospheres inside a cavity. The symmetron-mediated interaction induces an effective coupling which leads to a measurable splitting in the optomechanical resonance spectrum. We forecast constraints in the regime $\mu \sim 10^{-2}$eV-$10^{-4}$ eV, which shows that this approach can improve existing laboratory bounds by up to several orders of magnitude, demonstrating the sensitivity of optomechanical spectroscopy to screened fifth forces. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) External magnetic field influence on massive binary black hole inspiral gravitational waves and its similarity with environmental effects https://arxiv.org/abs/2603.05084 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.05084v1 Announce Type: new Abstract: Magnetic fields represent a critical component of astrophysical research, laying the foundation for interpreting high-energy astrophysical activity across galactic scales. In this work, we investigate the parametrized post-Einsteinian (ppE) waveform imprints induced by the external magnetic fields of Bertotti-Robinson and Bonnor-Melvin black holes, with the aim of distinguishing such magnetic effects from environmental influences--particularly for massive black holes posited to reside at galactic centers. We first compute the ppE frequency-domain waveform for a small black hole inspiraling into a massive Kerr-Bertotti-Robinson (KBR) black hole, which corresponds to a Kerr black hole embedded in an external magnetic field. We find that the leading-order correction arising from the magnetic field is at the $-2$ post-Newtonian (PN) order relative to the quadrupole term, while the next-leading-order correction is at $-1.5$ PN, originating from the spin of the black hole. We further examine the effects of a spinning Kerr-Bonnor-Melvin (KBM) black hole, whose leading-order magnetic correction is at $-3$ PN (consistent with the preceding result), whereas its spin-induced correction is also at $-1.5$ PN. The leading-order ppE corrections for both KBR and KBM black holes do not appear degenerate with any modified theory of gravity effects; nonetheless, we demonstrate that they resemble the gravitational pull contributions from additional matter with power-law distributions of index $\gamma=1$ and $\gamma=0$, respectively. As a result, future gravitational wave (GW) observations detecting $-3$ or $-2$ PN order corrections will infer their origin as either magnetic field effects or matter environmental influences. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Strong breaking of black-hole uniqueness from coexisting scalarization mechanisms https://arxiv.org/abs/2603.05064 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.05064v1 Announce Type: new Abstract: Black-hole uniqueness, i.e., the statement that all stationary vacuum black holes in the universe are described by the Kerr solution, is expected to break in theories beyond General Relativity. This breaking can take a particularly strong form, if several branches of black-hole solutions beyond the Kerr solution coexist. We find an example of a theory that exhibits such strong breaking. In this theory, a cubic coupling of a scalar field to the Gauss-Bonnet invariant triggers black-hole scalarization through a non-linear instability of the Kerr solution. At large spin, curvature-induced and spin-induced scalarization mechanisms compete at fixed sign of the coupling. This results in a rich phase structure of black-hole solutions and continuous as well as discontinuous transitions between the different branches of black holes. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Observational and Thermodynamic aspects of one-dimensional Dark Energy EoS parametrization models https://arxiv.org/abs/2603.05009 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.05009v1 Announce Type: new Abstract: We examine the observational viability and physical implications of the Gong-Zhang (GZ) dark--energy equation-of-state parametrizations using exclusively late-time cosmological probes. Two one-dimensional parametrization models, GZ-Type~I and GZ-Type~II, are constrained with Type~Ia supernovae (Union3, Pantheon+SH0ES, and DES-SN5YR), DESI baryon acoustic oscillations, and cosmic chronometer measurements of $H(z)$. Bayesian inference combined with information-criteria diagnostics shows that both parametrizations provide competitive alternatives to $\Lambda$CDM, while the GZ-Type~II model is consistently favored, exhibiting reduced parameter degeneracy and stronger Jeffreys-scale support. Beyond background expansion tests, we employ configuration entropy as a thermodynamically motivated probe of structure formation. We demonstrate that the entropy-production rate sensitively traces the impact of dynamical dark energy on late-time gravitational clustering while preserving standard early-time behavior. Our results establish the Gong-Zhang framework as a physically transparent and observationally consistent extension of $\Lambda$CDM, with configuration entropy providing a complementary diagnostic of late-time cosmic acceleration. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) A loop quantization of the marginally bound Lema\^itre-Tolman-Bondi dust model https://arxiv.org/abs/2603.04995 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04995v1 Announce Type: new Abstract: We present a loop quantization of the marginally bound Lema\^itre-Tolman-Bondi (LTB) model, describing the gravitational collapse of pressureless dust in spherical symmetry. The full quantum LTB model is constructed as a collection of non-interacting shells, each governed by an individual single-shell loop quantum dynamics. We show that the single-shell evolution is non-singular and that wave packets initially peaked on a collapsing trajectory undergo a bounce at Planckian energy densities and subsequently follow an expanding classical trajectory, resolving the classical central curvature singularity. We also compare the loop quantum theory with the Wheeler-DeWitt quantization of the same model and assess the accuracy of the loop quantum gravity effective theory in reproducing the full quantum dynamics. Specifically, we find that initially collapsing wave packets generically develop an interference pattern at the bounce, which suppresses the accuracy of the effective theory near the center of the dust cloud. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Dyonic hairy black holes in $U(1)$ gauge-invariant scalar-vector-tensor theories: Cubic and quartic interactions https://arxiv.org/abs/2603.04884 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04884v1 Announce Type: new Abstract: We construct and classify asymptotically flat, static, spherically symmetric hairy black hole solutions in $U(1)$ gauge-invariant scalar-vector-tensor (SVT) theories carrying both electric and magnetic charges. Extending previous studies beyond the quadratic sector, we systematically incorporate cubic and quartic interaction terms in the presence of the magnetic charge. We derive a consistency condition for the quartic interaction that eliminates higher-order derivative terms induced by the magnetic charge, ensuring the theory remains second-order. We classify the obtained solutions based on their symmetry properties: shift-symmetric couplings yield secondary hair governed by the Noether current, whereas $\phi$-dependent interactions generate primary hair. Crucially, our analysis reveals that the magnetic charge plays a key role in activating specific interaction sectors such as the cubic coupling $\tilde{f}_3$, which does not appear in the field equations in purely electric configurations. We identify solution branches that are intrinsic to the magnetic charge, as they cease to exist in the vanishing monopole limit ($P\to 0$). Furthermore, we demonstrate that the scalar hair exhibits distinct asymptotic decay rates depending on the interaction type, suggesting possible variations in observational signatures. Finally, we verify the global regularity of these solutions by connecting analytic expansions with numerical integration. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Inflation in fractional Newtonian cosmology https://arxiv.org/abs/2603.04712 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04712v1 Announce Type: new Abstract: In this paper, we investigate the evolution of the early universe within the framework of fractional Newtonian cosmology. By constructing a suitable fractional potential, we show that the cosmological evolution can naturally originate from a non-singular pre-inflationary regime. We find a natural transition time, separating the pre-inflationary and inflationary regimes, characterized by the balance of the corresponding forces. By analyzing the dynamics near the transition time, we show that the inflationary phase emerges as a stable dynamical attractor. We show that the fractional force vanishes and undergoes a sign change at a point very close to the end of inflation. We then determine the small separation between the force zero point and the end of inflation, and show that it leads to a meaningful relation between the number of $e$-folds and the fractional parameter $\alpha$, ensuring consistency with observations and resolving the horizon problem. Moreover, our results demonstrate the existence of a graceful exit from inflation, followed by an exact radiation-dominated solution with the standard time dependence and an $\alpha$-dependent normalization. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Going into a tailspin near the abyss: analytic solutions for spinning particles on near equatorial, plunging orbits in Kerr spacetime https://arxiv.org/abs/2603.04682 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04682v1 Announce Type: new Abstract: This work presents, the first time, analytic solutions for the nearly equatorial, plunging motion of a spinning test-particle in Kerr spacetime. The equations of motion are solved at first-order in the small-body spin for all classes of plunging orbits with energy $E < 1$. The solutions incorporate the small precession of the orbital plane caused by the precession of the particle's spin. Additionally, we present the correction to the radius of the innermost bound circular orbit in closed form, and introduce a novel, Keplerian-like parametrization for generic plunging orbits. Our solutions will be useful in the modelling of inspiral-merger-ringdown waveforms with self-force methods and black hole perturbation theory. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Junction Conditions for General Gravitational Theories https://arxiv.org/abs/2603.04645 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04645v1 Announce Type: new Abstract: The junction conditions for general theories of gravity based on actions that depend on arbitrary functions of the curvature scalar invariants (including differential invariants) are obtained using the distributional formalism. In case of the existence of thin shells, a general expression for the shell energy-momentum is presented. The generalized Israel conditions are also obtained. The conditions for a proper matching, without shells, are also derived. The main results are: (i) shells arise if the $m$th-covariant derivative of the Riemann tensor is continuous at the matching hypersurface, where $m$ is the maximum order appearing in the Lagrangian density; (ii) a proper junction without thin shells requires further that the $(m+1)$-th derivative be also continuous, (iii) theories with $m=0$ that are quadratic in the scalar curvature invariants are special and unique for they allow for discontinuities of the Riemann tensor resulting in the existence of {\em thin shells and gravitational double layers} and (iv) General Relativity and $F(R)$ theories are extraordinary theories that admit shells of curvature (i.e. impulsive gravitational waves) because other theories require the absence of jumps of the second fundamental form across the matching hypersurface. All results are derived for a minimal coupling with the matter, but the strategy would be analogous for more general couplings. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Cosmological black holes in the inflationary epoch https://arxiv.org/abs/2603.04590 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04590v1 Announce Type: new Abstract: We investigate the evolution of black holes present during the inflationary epoch, assuming they are dynamically coupled to the cosmological background through a generalized McVittie geometry, such that their gravitational mass scales with the cosmic scale factor. Adopting Starobinsky's $\mathcal{R}^2$ inflation model, we analyse the combined effects of cosmological coupling, Hawking evaporation and radiation accretion during the subsequent cosmic eras: inflation, radiation, matter, and dark energy. Requiring the black hole event horizon to remain smaller than the particle horizon at all times yields an upper bound on the mass parameter. Radiation accretion during the radiation era further constrains the parameter space to prevent runaway growth. Hawking evaporation sets a lower bound on the initial mass to ensure survival through inflation. We find that only black holes formed within a narrow initial mass range during inflation can persist to the present day, reaching a maximum mass of $M(t_0) \simeq 1.043\times10^{-3} M_\odot$. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Nonlinear Dynamics in General Relativity https://arxiv.org/abs/2603.04501 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04501v1 Announce Type: new Abstract: Black holes and gravitational waves are consequences of the nonlinear character of the Einstein equations. Yet, the remarkable properties of General Relativity point to the existence of other effects. Here we uncover new nonlinear facets of gravity. We establish higher harmonic generation, spectral broadening and focusing in the Einstein Klein-Gordon system. In vacuum, we show that scattering of monochromatic waves at quadratic order is weakly sensitive to frequency, at large wavelengths. These aspects can both explain the seemingly smooth behavior of mergers, but also caution us against too simplistic an interpretation of waveforms. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Can Light Cross a Singularity? Exact Solutions from Analogue Gravity https://arxiv.org/abs/2603.05285 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.05285v1 Announce Type: new Abstract: Using a simple spacetime hosting a strong curvature naked singularity, we employ an analogue gravity model to study electromagnetic fields in this background. We find exact solutions to the full set of electrostatic and electrodynamic equations that remain regular even in the presence of the singularity. Moreover, certain solutions sustain a regular and bounded power flux across the singularity, suggesting that electromagnetic energy may be transmitted through it. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Aspects of Relativity in Flat Spacetime https://arxiv.org/abs/2603.04574 Fri, 06 Mar 2026 00:00:00 -0500 arXiv:2603.04574v1 Announce Type: new Abstract: A monograph on the mathematical aspects of Special Relativity, focusing on the Lorentz group and the properties of relativistic transformations in mechanics and electrodynamics. Manuscript of published book, with an added appendix. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Lorentzian-Euclidean singularity-free solutions to gravitational collapse https://arxiv.org/abs/2603.03934 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03934v1 Announce Type: new Abstract: This study explores singularity-free solutions to the static, spherical symmetric Einstein equations with the standard Schwarzschild solution as a boundary condition. Imposing the absence of curvature singularities and requiring differentiability of the time component of the metric leads to a sign change across the horizon, violating the Principle of Equivalence locally. We find a solution within the event horizon with a simple ``cosmological constant'' stress-energy tensor. Considering the impact of sign change to a compact stellar remnant, modeled by an incompressible perfect fluid obeying the Tolman-Oppenheimer-Volkoff equation, we rediscover the same geometry, indicating both mathematical and physical feasibility of the model. We also find a new theoretical limit M/R=3/8, which is lower than the Buchdahl limit of M/R=4/9 for the density of a perfect fluid that will recede behind an event horizon. The equation of state is discussed, and we propose that the final state is described by a Higgs-like free scalar field. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Local observers in stationary axisymmetric dust spacetimes https://arxiv.org/abs/2603.03924 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03924v1 Announce Type: new Abstract: In this work, we construct a locally inertial reference system adapted to a geodesic observer in stationary, axisymmetric dust solutions of the Einstein equations employed as effective models of a portion of a galactic disc. To ensure a consistent spatial orientation among different local observers, we also introduce the radially locked reference system, in which one spatial axis is aligned with the radial direction defined by null geodesics passing through the galactic center. Within this framework, we analyze how the dust configuration is described by such observers by computing the frequency shift of photons exchanged between pairs of dust geodesics. Building on this construction, we outline a procedure to reconstruct spectroscopic and astrometric relative velocities with respect to locally inertial observers, providing a coherent foundation for the study of galactic kinematics in a fully general relativistic context. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Photon Spheres and shadow of Schwarzschild black hole on the EUP framework https://arxiv.org/abs/2603.03660 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03660v1 Announce Type: new Abstract: An explicit correspondence is established between the Extended Uncertainty Principle (EUP) and the metric function by directly relating the radiation temperature function modified by EUP to the modified spacetime metric. Utilising this modified metric, we subsequently derive the corresponding thermodynamic quantities of the black hole, and calculate the photon sphere radius and the size of the black hole shadow. The results of the study indicate that, in comparison with Schwarzschild black holes, the position of the event horizon remains constant under EUP modifications. However, the photon sphere radius increases with growing EUP parameters, while the shadow size decreases with increasing parameters, demonstrating that EUP induces optical shift phenomena. By comparing with observations of the galactic centre black hole $\text{Sgr}{{\text{A}}^{*}}$ from the Event Horizon Telescope, new constraints are established on EUP parameters. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Analogue Hawking radiation in nonlinear quantum optics https://arxiv.org/abs/2603.03525 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03525v1 Announce Type: new Abstract: The Hawking effect can be understood as a broad kinematic phenomenon associated with mode behavior near a horizon. While astrophysical black holes produce one specific realization of this radiation, this perspective inspires extensive theoretical and experimental efforts to create event horizons in diverse physical systems to observe the resulting analogue Hawking emission. One of the most successful realizations is the fiber-optical analogue, based on nonlinear quantum optics. In these notes, we introduce and motivate this system while outlining the theoretical concepts underlying the gravitational analogy. Finally, we review key experiments and discuss their impact on the field. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Accelerating Bertotti-Robinson Black Holes in a Uniform Magnetic Field https://arxiv.org/abs/2603.03494 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03494v1 Announce Type: new Abstract: We study the Hawking temperature, geodesic motion, and observable signatures of the accelerating Bertotti-Robinson (BR) spacetime, a vacuum black-hole solution deformed by a uniform magnetic field $B$ and an acceleration parameter $\alpha$. In the timelike sector, we derive the effective potential for massive particles, determine the specific energy and angular momentum for equatorial circular orbits, and determine how $(B,\alpha)$ shifts the ISCO; we also illustrate representative trajectories of massive particles. We then compute the radial and latitudinal epicyclic frequencies for small perturbations about circular orbits, quantifying how the magnetic field and acceleration modify local radial and vertical stability. In the null sector, we derive the photon effective potential and obtain analytical expressions for the photon-sphere radius, critical impact parameter, and shadow radius, complemented by photon trajectories, the effective radial force, and the Lyapunov exponent controlling the instability of circular null orbits; we also provide parameter-space maps for the photon sphere and shadow. Finally, we obtain the energy emission rate emitted from the black hole, showing how the acceleration parameter and the magnetic field affect this. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Slowly rotating charged BTZ black hole solutions in Palatini Chern-Simons gravity https://arxiv.org/abs/2603.03436 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03436v1 Announce Type: new Abstract: We consider a metric-affine formulation of Chern-Simons modified gravity in 2 + 1 dimensions. The theory is built requiring projective invariance, and the structure of the equations is analyzed using a decomposition in terms of scalar, vectorial, and purely tensorial objects. This approach allows us to implement a perturbative approach to study the corrections that emerge around a given background solution, for which we consider a BTZ charged, non-rotating metric. We show that conditions on model parameters are necessary to keep perturbations under control, yielding a rotating solution with a constant angular momentum and magnetic field at the horizon, and a smooth decay further away. We comment on the possibility of going beyond the leading order in perturbations and on its dynamical implications. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Braneworld cosmology in $f(\mathbb{Q})$ gravity https://arxiv.org/abs/2603.03435 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03435v1 Announce Type: new Abstract: This work investigates the cosmology of a thick brane within the context of $f(\mathbb{Q})$ gravity, an extension of symmetric teleparallelism. Using a five-dimensional Friedmann-Lema\^itre-Robertson-Walker metric, we solve the field equations to obtain dynamic solutions for the scale factor. We demonstrate that the effective cosmological constant on the brane naturally emerges as a function of the extra dimension $\Lambda(y)$, being both generated and confined by the curved geometry of the bulk. We analyze two distinct regimes: Randall-Sundrum-type thin brane and thick brane through the Sine-Gordon model. Our model reproduces accelerated expansion solutions without requiring the introduction of a fundamental cosmological constant on the brane, showing that the cosmic acceleration emerges as a consequence of the brane's embedding and the gravitational dynamics in the bulk . The variation of the $c_i$ parameters in symmetric teleparallelism enables different cosmological scenarios, including de Sitter-type expansion, contraction, and oscillatory solutions. The results indicate that the brane's position in the bulk determines its cosmology, providing a geometric explanation for the smallness of the observed cosmological constant. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Lower-dimensional Gauss-Bonnet gravity black holes with quintessence https://arxiv.org/abs/2603.03408 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03408v1 Announce Type: new Abstract: In this paper, we study the $D\to3$ limit of Gauss-Bonnet gravity with quintessential matter, obtaining exact solutions that extend the BTZ metric through higher-curvature terms and quintessence coupling. The solutions exhibit a single event horizon whose radius decreases with increasing quintessence parameter $\omega_q$, while developing a curvature singularity at the origin for non-vanishing quintessence. The geodesic analysis reveals stable circular photon orbits exist exclusively for phantom-like quintessence ($\omega_q < -1$). Thermodynamically, the system is stable, since the specific heat is positive, and with evaporation it evolves to stable remnants whose characteristic size decreases as $\omega_q$ increases, with complete evaporation prevented by quintessence effects. Furthermore, we find that all physical quantities intrinsically depend on the parameter $\alpha$ of the Gauss-Bonnet extension.These results demonstrate the profound influence of quintessential matter on both geometric and thermodynamic properties of (2+1)-dimensional black holes, offering new perspectives on gravitational theories in lower dimensions and black hole final states. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) The perturbation solutions to the Blandford-Znajek mechanism in the Kerr-Sen black hole https://arxiv.org/abs/2603.03391 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03391v1 Announce Type: new Abstract: We investigate the steady, axisymmetric, force-free magnetosphere of Kerr-Sen black hole (BH) within the framework of the Einstein-Maxwell-dilaton-axion (EMDA) theory. By perturbatively solving the nonlinear Grad-Shafranov (GS) equation, we determine the magnetic field configuration and quantify the influence of the dilaton parameter $r_2$ on the energy extraction rate and radiative efficiency. Our results show that both the energy extraction power and the radiative efficiency increase with $r_2$, exceeding those of the standard Kerr BH, whereas the extraction efficiency remain consistent with the Kerr case. In addition, we perform $\chi^2$ statistical analysis using observational data from six binary BH systems, which indicates that the Kerr BH currently provides a better fit for bulk Lorentz factors $\Gamma = 2$ and $5$. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Dark Energy from Entanglements with Mirror Universe https://arxiv.org/abs/2603.03385 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03385v1 Announce Type: new Abstract: We investigate a possible resolution of the dark energy problem within a pair-universe framework, in which the Universe emerges as an entangled pair of time-reversed sectors. In this setting, a global zero-energy condition allows vacuum energy contributions from the two sectors to cancel, alleviating the need for extreme fine-tuning. We propose that the observed dark energy does not originate from vacuum fluctuations but instead arises as an effective entanglement energy between the visible universe and its mirror counterpart. Treating the cosmological constant as an integration constant fixed by boundary conditions rather than a fundamental parameter, we show that the cosmological equations can be formulated without explicitly introducing vacuum energy. By imposing physically motivated boundary conditions at the cosmological event horizon, we obtain an integration constant consistent with the observed dark energy density. The parallel mirror world scenario thus provides a unified framework that may simultaneously explain the origins of dark energy and dark matter. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) The $T^{\mu\nu}$ of the conformal scalars https://arxiv.org/abs/2601.05311 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2601.05311v2 Announce Type: replace Abstract: We construct the unique primary energy-momentum tensor $T^{\mu\nu}$ for the conformal free scalar with scaling dimension $\Delta=d/2-\zeta$ as a sum of Gegenbauer polynomials. For integer $\zeta$, the sum truncates at order $\zeta$, compactly reproducing all known results; for the nonlocal case of real $\zeta$, it is an infinite sum, with a two-parameter extension that reflects the nonuniqueness of the nonlocal geometric coupling. We find $T^{\mu\nu}$ by imposing off-shell conservation and tracelessness, and then directly solving the primary condition in momentum space. In the integer $\zeta$ case, we reproduce the known two-point function, and confirm the match with the $T^{\mu\nu}$ computed from Juhl's formulae for the GJMS operators (the Weyl-covariant upgrades of $(-\partial^2)^\zeta$), an equality following from the descent of Weyl covariance to conformal invariance. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Holographic shear correlators at low temperatures, and quantum $\eta/s$ https://arxiv.org/abs/2512.20443 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2512.20443v2 Announce Type: replace Abstract: The strongly-coupled 3-dimensional theory, holographically dual to black branes at fixed chemical potential $\muext$ and temperature $T \ll \mu$ is considered in AdS$_4$ Einstein-Maxwell theory. The retarded Green's functions at frequency $\omega$ is calculated using holography in the regime $\omega, T \ll \muext$ but otherwise arbitrary. When the transverse space has finite volume, there is a non-zero energy scale $E_\text{gap}$, scaling as $1/\mu$ for large $\mu$, below which quantum-gravitational corrections due to the fluctuations of the nearly-gapless Schwarzian modes become important. Such corrections to the retarded Green's function are calculated at different relative values of $\omega$, $T$, and $E_\text{gap}$. The $\omega \to 0$ limit is used to define the shear viscosity $\eta$. As the temperature is lowered below $\mu$, quantum corrections are found to increase the value of $\eta$ with respect to its semiclassical value.The quantum-corrected result for $\eta$ diverges as $\sqrt{E_\text{gap}/T}$ at $T \ll E_\text{gap}$, in accord with corresponding results for the absorption cross section. The quantum result for the ratio $\eta/s$, where $s$ is the entropy density, dips below the semiclassical limit of $1/4\pi$ when $E_\text{gap} \ll T \ll \mu$,then turns back to increase towards lower temperatures, and finally diverges at temperatures much below $E_\text{gap}$. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Elastic Kink-Meson Scattering in the $\Phi^4$ Double-Well Model https://arxiv.org/abs/2512.17746 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2512.17746v2 Announce Type: replace Abstract: We calculate the leading order amplitude and probability for the elastic scattering of an elementary meson and a kink in the $\phi^4$ double-well model. Classically, the kink is reflectionless, and so the leading contribution arises at one loop. At this order, the scattering amplitude exhibits a pole when the incoming meson energy is twice the shape mode energy, corresponding to the excitation of an unstable resonance with the twice excited shape mode. We expect that higher order corrections will give this resonance a width equal to the inverse of the known lifetime of this unstable excitation. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Anomaly footprints in SM+Gravity https://arxiv.org/abs/2510.25217 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2510.25217v2 Announce Type: replace Abstract: This is a follow-up of arXiv:2412.07470 [hep-th]. A simplified version of the SM plus gravity, put forward there, is presented here and some of its aspects delved into. The basic structure consists of two sectors, left and right, with chirally mirror fermions and scalars, as well as $SU(3)$ and $U(1)$ gauge fields, while the $SU(2)$ gauge fields as well as the metric are in common to both sectors. This structure is dictated by the request to cancel all dangerous anomalies. The left sector consists of the fermion, gauge and scalar fields of the SM, now minimally coupled to gravity. The right sector is a mirror image of the left, with distinct fields, except the metric and the $SU(2)$ gauge potentials. The first new aspect is the proposed and motivated interpretation of the right sector as the dark matter one. The second new subject covered here is Weyl symmetry and its possible application to cosmology and its theoretical fallout on unitarity and renormalization of the model. A background solution of the Weyl invariant theory is derived, which may apply to the very early stages of the universe. This solution also suggests interesting applications to the cosmological constant problem. On the quantum field theory side the subject of Weyl symmetry and Weyl anomalies is reviewed and, among other things, an application of the WZ terms is illustrated to the problem of one-loop quantization of the model which may avoid negative norm states. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Can Newtonian Gravity Produce Quantum Entanglement? https://arxiv.org/abs/2510.23584 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2510.23584v4 Announce Type: replace Abstract: We investigate whether Newtonian gravity can generate quantum entanglement between mesoscopic quantum bodies modeled as superposed mass quadrupoles using three complementary approaches: mini-superspace, semiclassical gravity, and stochastic gravity. We systematically analyze gravitationally induced entanglement (GIE) mechanisms and the conditions under which they can arise. Our results support the GIE hypothesis by showing that the mini-superspace framework, which quantizes the parity of the gravitational tidal field, can entangle spatially separate quantum bodies. In contrast, the semiclassical and stochastic gravity models, in which the tidal gravitational field sourced by the quantum bodies remains classical, fail to entangle the final state. These findings clarify recent claims that classical gravity might induce entanglement, and reveal how perturbative treatments can lead to misleading conclusions. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Local gauge invariant operator on isometry breaking background https://arxiv.org/abs/2510.22879 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2510.22879v2 Announce Type: replace Abstract: Whereas local field operators play the crucial role in reconciling quantum mechanics and special relativity, they are not trivially compatible with the diffeomorphism invariance of gravity. In order to address this issue, we consider the background geometry which breaks the isometry spontaneously. Then the local gauge invariant operator can be constructed through the St\"uckelberg mechanism, where the fluctuation of the metric in the direction of the isometry breaking combines with that of matter whose classical solution breaks the isometry. This is equivalent to introducing the clock and the rod to promote the local field operators to the gauge invariant ones. A typical example is the curvature perturbation in quasi-de Sitter space arising from the spontaneous breaking of the timelike isometry. We also discuss the features of the local gauge invariant operator when the spacelike isometry is spontaneously broken. Meanwhile, even if the local gauge invariant operators exist, it does not guarantee the reliable construction of the gauge invariant operators on the local region like the island, which is regarded as an essential ingredient to resolve the black hole information paradox. This is because the fluctuation of the spacetime point is accumulated in time, which in fact also gives rise to eternal inflation in quasi-de Sitter space. In order to suppress the fluctuation at late time, the isometry must be strongly broken by the background. In the case of the evaporating black hole, it may be achieved by the transition to the higher dimensional black hole. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Quantum Corrections to $\eta/s$ from JT Gravity https://arxiv.org/abs/2510.21602 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2510.21602v3 Announce Type: replace Abstract: We revisit the computation of the shear viscosity to entropy ratio $\eta/s$ at finite chemical potential in a holographic model that takes into account the quantum fluctuations in the IR region of near-extremal black branes. Such quantum corrections can be computed from JT gravity and generate non-trivial temperature dependence for $\eta/s$, which deviates from the universal $1/4\pi$ result. In the semi-classical regime, $\eta/s$ attains a minimum which is below the KSS bound, generated by the presence of the quantum effects. In the quantum regime at lower temperatures, $\eta/s$ increases and is well above the KSS bound. We also compare the shear viscosity to the quantum-corrected absorption cross-section of near-extremal black holes, and find agreement. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Probing the bubble interior with entanglement entropy and bulk-cone singularities https://arxiv.org/abs/2509.21632 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2509.21632v2 Announce Type: replace Abstract: In the thin wall approximation, we study a class of asymptotically AdS black holes which contain a spherically symmetric vacuum bubble with a different (positive or negative) cosmological constant. Collapsing, expanding, and static bubble solutions are considered. Among these, expanding bubbles with positive cosmological constant can provide a way to apply the AdS/CFT correspondence to describe the physics of an expanding universe. We systematically study the causal structure of the solutions as a function of the cosmological constant, the mass of the black hole, and the tension of the bubble. We then compute the holographic entanglement entropy for a class of boundary subregions using extremal codimension-two surfaces as a probe. For collapsing bubbles, we find examples in which the entanglement entropy also explores the geometry inside the black hole bifurcation surface. As a complementary way to probe the interior of the bubble, we investigate almost-null radial geodesics related to the bulk-cone singularities of boundary two-point correlators. While the bulk-cone singularities for collapsing and expanding bubbles are consistent with thermalization at late time, static bubbles violate thermalization and exhibit properties similar to those of scar states. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Non-Factorizing Interface in the Two-Dimensional Long-Range Ising Model https://arxiv.org/abs/2505.15018 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2505.15018v2 Announce Type: replace Abstract: The factorization proposal claims that the co-dimension one "pinning defect", on which a local relevant operator is integrated, factorizes the space into two halves in general conformal field theories in the infrared limit. In this letter, we study a two-dimensional long-range Ising model at criticality with a line defect or an interface, which physically corresponds to changing the local temperature on it. We show that in the perturbative regime, it is not factorizing even in the infrared limit. An intuitive explanation of the non-factorization is that the long-range Ising model is equivalent to a local conformal field theory in higher dimensions. In this picture, the space is still connected through the "extra dimension" across the defect line. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Probing black hole entropy via entanglement https://arxiv.org/abs/2505.08012 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2505.08012v2 Announce Type: replace Abstract: In this paper, we develop a method to extract the Bekenstein-Hawking entropy of $D$-dimensional black holes using the entanglement entropy of a lower-dimensional conformal field theory (CFT). This approach relies on two key observations. On the gravitational side, the near-horizon geometry of extremal black holes is AdS$_{2}$, and the Bekenstein-Hawking entropy is entirely determined by this two-dimensional geometry. Moreover, the higher-dimensional spherical part of the black hole metric is absorbed into the $D$-dimensional Newton's constant $G_{N}^{\left(D\right)}$, which can be effectively reduced to a two-dimensional Newton's constant $G_{N}^{\left(2\right)}$. On the field theory side, the entanglement entropy of two disconnected one-dimensional conformal quantum mechanics (CQM$_{1}$) can be calculated. According to the Ryu-Takayanagi (RT) prescription, this entanglement entropy computes the area of the minimal surface in the AdS$_{2}$ geometry. Since the near-horizon region of the black hole and the emergent spacetime derived from the entanglement entropy share the same Penrose diagram -- with both the black hole event horizon and the RT surface corresponding to specific points on this diagram -- the Bekenstein-Hawking entropy can be probed via entanglement entropy when these points coincide. This result explicitly demonstrates that the entanglement across the event horizon is the fundamental origin of the Bekenstein-Hawking entropy. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Comparing top-down and bottom-up holographic defects and boundaries https://arxiv.org/abs/2504.13244 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2504.13244v2 Announce Type: replace Abstract: In this work we consider domain walls and end-of-the-world branes in AdS/CFT, holographically dual to codimension-one conformal defects and conformal boundaries respectively. In this setting there is an analogue of the ``bulk point'' singularity in boundary correlation functions, which we use to compare top-down and bottom-up constructions of these systems. For example, for a range of parameters the D3/D5 boundary CFT cannot be imitated by a tensionful end-of-the-world brane coupled to Einstein gravity, and in another range it can be modeled with a negative tension brane. Along the way we compute the central charge $b$ for the M2/M5 boundary CFT. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Energy-Momentum Tensor and D-term of Baryons in Top-down Holographic QCD https://arxiv.org/abs/2503.19492 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2503.19492v3 Announce Type: replace Abstract: We study the energy-momentum tensor of a baryon in a top-down holographic QCD. In holographic QCD, the baryons are represented as solitons in a 5-dimensional gauge theory. We obtain the soliton solution by solving the equations of motion numerically. Using this result, the energy-momentum tensor and related quantities such as the mass, mean square radii, and the D-term (druck term) are computed. The evaluated D-term is about -2.05, whose absolute value is significantly larger than that in the previous work arXiv:2206.06578. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Dynamics of Simplest Chiral Gauge Theories https://arxiv.org/abs/2209.09287 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2209.09287v2 Announce Type: replace Abstract: Arguably, the simplest chiral gauge theories are $\mathrm{SO}(10)$ with $N_f$ fermion fields in the spinor representation {\bf 16}. We study their dynamics using their supersymmetric limits perturbed by an infinitesimal anomaly-mediated supersymmetry breaking as a guide. We predict the theory is gapped for $N_f=1,2$, while the $\mathrm{SU}(N_f)$ global symmetry is broken to $\mathrm{SO}(\mathrm{N}_f)$ for moderately large $N_f \geq 3$. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Mixed-state Phases from Higher-order SSPTs with Kramers-Wannier Symmetry https://arxiv.org/abs/2603.03455 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03455v1 Announce Type: cross Abstract: Mixed-state phases have recently attracted significant attention as a generalization beyond their pure-state counterparts. Prominent examples include mixed-state symmetry-protected topological (mSPT) phases and the strong-to-weak symmetry breaking (SWSSB) phases. It has been shown recently that mSPT phases admit a holographic dual description in terms of higher-order subsystem SPT phases. In this work, we investigate the mixed-state phases obtained by tracing out the bulk degrees of freedom of higher-order subsystem SPT phases protected by non-invertible symmetries. We find that the resulting mixed states exhibit the coexistence of the symmetry-protected topological order and SWSSB. We also use the interface as a probe to characterize the mixed state phases, and specifically, when there is no local modification to preserve the symmetries across the interface, the two sides of the interface are in distinct phases. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Casimir Effect for a Massive Scalar Field in Lorentz-Violating Aether Compactification https://arxiv.org/abs/2603.04371 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04371v1 Announce Type: new Abstract: This work investigates the influence of Lorentz symmetry breaking, introduced by an aether-like field $\alpha_\phi$, on the Casimir effect within a five-dimensional flat spacetime. By considering a quasiperiodic condition regulated by the parameter $\beta$ and an extra dimension compactified at scale $b$, we derive closed-form expressions for the Casimir energy and the resulting force between two parallel plates under Neumann boundary conditions. Our results demonstrate that $\beta$ acts as a crucial control parameter, enabling a continuous transition between attractive and repulsive regimes, with a characteristic symmetry around $\beta = 0.5$. We show that the Lorentz-violating parameter $\alpha_\phi$ functions as an enhancement factor, significantly amplifying the vacuum interaction, while the geometric ratio $a/b$ proves decisive for system stabilization. Specifically, we find that the high-compactification regime leads to a plateau in the Casimir force, effectively stabilizing the interaction. Furthermore, we analyze the mass spectrum of the field, recovering standard geometric forms in the massless limit and demonstrating that while light fields ($M \ll 1$) exhibit subtle quadratic corrections, heavy fields ($M \gg 1$) lead to an exponential suppression of the Casimir effect. The interplay between Lorentz violation and extra-dimensional compactification provides a rich mechanism with potential applications in the modulation of vacuum-induced interactions at micro and nano scales. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Heterotic horizons and AdS$_3$ backgrounds that preserve 6 supersymmetries https://arxiv.org/abs/2603.04120 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04120v1 Announce Type: new Abstract: We prove, under suitable global assumptions, that the only heterotic horizons with closed 3-form field strength that preserve strictly 6 supersymmetries have spatial horizon section diffeomorphic to $SU(3)$, up to identifications with the action of a discrete group. Under similar assumptions, which include the compactness of the transverse space, we demonstrate that there are no heterotic AdS$_3$ solutions that preserve 6 supersymmetries. The proof is based on a topological argument. We also re-examine the conditions required for the existence of such backgrounds that preserve 4 supersymmetries focusing on those that admit an additional $\oplus^2\mathfrak{u}(1)$ symmetry. We provide some additional explanation for the existence of solutions and point out the similarities that these conditions have with those that have recently emerged in the classification of compact strong 6-dimensional Calabi-Yau manifolds with torsion. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Scattering of kinks in Frankensteinian potentials: Kinks as bubbles of exotic mass and phase transitions in oscillon production https://arxiv.org/abs/2603.04101 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04101v1 Announce Type: new Abstract: We present a dynamical picture of kink-anti-kink scattering in a pair of special, Frankensteinian potentials made of piece-wise quadratic and linear pieces. Specifically, we focus on models that support kinks without skin and core regions. We propose an intuitive interpretation for these models as being essentially free massive theories with a built-in particle-pair like production mechanism that enters into the dynamics above certain field-value thresholds. We present results concerning the kink's characteristics depending on these thresholds and the distribution of bouncing windows. We show that the second model exhibits a phase-transition-like property in which the nature of collisions switches from disintegration into a massive wave to production of oscillons for large segments of initial velocities when the field threshold is low enough. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) The indivisibility of a quantum-corrected AdS black hole with phantom global monopoles https://arxiv.org/abs/2603.03896 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03896v1 Announce Type: new Abstract: We study the indivisibility of a quantum-corrected AdS black hole involving two kinds of global monopoles, regular or phantom ones to declare the effects from the quantum fluctuation, monopole factors and the negative cosmological constant on the evolution of black holes. We focus our attention on the possibility that this kind of black holes break into their own two parts because of the second law of thermodynamics. We derive and calculate the entropies of the initial black hole and the broken parts respectively and the entropy difference relates to the black holes structure including the quantum-gravity oscillation, global monopoles and the influence from AdS environment. It is found that the two kinds of global monopoles both keep the black holes intact instead of splitting because the entropy difference is negative. The considerable quantum fluctuation compels the defference to be positive and the fragmentation of the black holes may happen in the case that the mass of one fragmented black hole is tiny and the other one's mass is huge. The AdS radius can increase the whole value of change in entropy and the difference near the midpoint of mass ratio will become positive, so the large enough radius may lead the isolated black hole to become two parts nearly equal in the mass. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) The Generalized Dirac Oscillator in Doubly Special Relativity: A Complexified Morse Interaction https://arxiv.org/abs/2603.03572 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03572v1 Announce Type: new Abstract: We study the one-dimensional Generalized Dirac Oscillator (GDO) under Doubly Special Relativity (DSR) kinematics. The GDO extends the Dirac oscillator by replacing the linear non-minimal coupling with a general interaction function $f(x)$, thereby generating broad families of exactly solvable relativistic models and, for suitable complex choices of $f(x)$, entering the domain of $\eta$-pseudo-Hermitian and $\mathcal{PT}$-symmetric dynamics with real spectra. We present a review of the factorization (supersymmetric) structure that decouples the GDO into partner Schr\"odinger-like Hamiltonians, and we clarify how pseudo-Hermiticity and $\mathcal{PT}$ symmetry provide consistent inner products and reality conditions for the spatial spectrum. We then embed these results into two representative DSR prescriptions: the Magueijo--Smolin (MS) and the Amelino--Camelia (AC) frameworks. In this approach, the spatial problem yields a real set $\{\epsilon_n\}$, while DSR deforms the algebraic reconstruction map between $\epsilon_n$ and the relativistic energies $E_n$. The MS model induces a branch-asymmetric deformation through an energy-dependent effective mass, whereas the AC model introduces a characteristic criticality through a momentum-sector deformation, resulting in an admissibility requirement of the form $\epsilon_n<4k^2$ in the leading-order realization adopted here. As an explicit illustration, we treat a pseudo-Hermitian complexified Morse interaction, discuss the interplay between the intrinsic Morse finiteness of bound states and DSR-induced truncations, and analyze the massless limit ($m=0$), where MS collapses to the undeformed energy map while AC remains deformed. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Asymptotic Quantum Gravity as an Infrared Geometric Theory https://arxiv.org/abs/2603.03501 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03501v1 Announce Type: new Abstract: We formulate the infrared sector of asymptotically flat quantum gravity in terms of asymptotic configurations accessible to external observers. Starting from the Regge-Teitelboim Hamiltonian that generates physical evolution in the presence of gravitational constraints, we perform a Born-Oppenheimer reduction separating slow asymptotic data from fast bulk gravitational fluctuations. We show that integrating out the fast sector induces a functional Berry connection over the space of asymptotic charges, so that the effective infrared dynamics is governed by parallel transport on this charge space. In this framework, infrared gravitational states are naturally organized into superselection sectors labelled by the holonomy of the induced connection, and the reduced density matrix obtained after tracing over ultraviolet bulk modes acquires a geometric contribution. This provides an effective geometric description of the asymptotic quantum gravitational sector, where quantization arises as a global consistency condition under adiabatic transport rather than as a spectral property of local bulk operators. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Dispersion relations of deeply virtual Compton scattering: investigating twist-4 kinematic power corrections https://arxiv.org/abs/2509.05059 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2509.05059v3 Announce Type: replace Abstract: In this paper we include kinematic power corrections up to twist-four to the deeply virtual Compton scattering dispersion relation. We demonstrate that, both for (pseudo-)scalar and spin-$1/2$ targets, the formal expression of the $n$-subtracted leading-twist dispersion relations is preserved. However, the expression of the subtracted constants is modified by the kinematic powers. Importantly, the minimal-subtracted dispersion relation for the helicity-conserving amplitude, previously thought to depend only on the Polyakov-Weiss $D$-term, now also depends on the double distributions $F$ and $K$. These results are consistent with the ones obtained previously in the literature. Such a mixing may be critical for the Jefferson Lab kinematic range, as it is not suppressed for typical values of $t$ and $Q^{2}$ in the valence region. We therefore expect a strong impact on attempts to extract pressure forces from DVCS data. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Genesis of baryon and dark matter asymmetries through ultraviolet scattering freeze-in https://arxiv.org/abs/2505.22710 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2505.22710v2 Announce Type: replace Abstract: We introduce a new mechanism for the simultaneous generation of baryon and dark matter asymmetries through ultraviolet-dominated freeze-in scatterings. The mechanism relies on heavy Majorana neutrinos that connect the visible Standard Model sector to a dark sector through the neutrino portal. Following reheating of the visible sector to a temperature well below the heavy neutrino masses, we show that 2-to-2 scattering processes can populate the dark sector and generate both baryon and dark matter asymmetries. In some parameter regions, the dominant source of baryon asymmetry can be charge transfer from the dark sector, a process we call dark wash-in. We also demonstrate that annihilation of the dark matter to massless states within the dark sector can deplete the symmetric population without destroying the net baryon charge to leave only an asymmetric dark matter abundance today. Depending on the specific model parameters, the observed baryon and dark matter abundances can be attained with heavy neutrino masses $M_N \gtrsim 10^{10}$ GeV, and dark matter masses in the range 0.1 GeV $\lesssim m_\chi \lesssim 10^3$ GeV if the dark matter relic abundance is mainly asymmetric and even lower masses if it is symmetric. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) The generic basis and flavour non-universal SMEFT https://arxiv.org/abs/2502.04634 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2502.04634v2 Announce Type: replace Abstract: Whenever an anomaly in the flavour sector appears, analyses are performed examining whether it can be explained by adding a small number of carefully-chosen flavour non-universal four-fermion SMEFT operators. These analyses are typically carried out in the down or the up basis, i.e., it is assumed that the weak and mass eigenstates are the same for the left-handed down-type or up-type quarks. In these bases, there is no dependence on the matrices that transform from the weak to the mass basis, and which are unmeasurable in the Standard Model. In this paper, we argue that it is better to use a generic weak basis, in which no assumptions about the alignment of weak and mass eigenstates are made. The analysis now directly includes elements of the transformation matrices. By doing a fit to the data, it is possible to both determine if the flavour anomaly can be explained and extract the transformation matrices. In principle, this can be extended to a complete reconstruction of the Yukawa matrices. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Correlators of heavy-light quark currents in HQET: Perturbative contribution up to 4 loops and beyond https://arxiv.org/abs/2411.11080 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2411.11080v3 Announce Type: replace Abstract: The perturbative contribution to the correlator of two HQET heavy-light currents expanded in light-quark masses up to quadratic terms is calculated up to 4 loops. The leading large-$\beta_0$ limit is also considered, so that terms with the highest degrees of $n_f$ are calculated to all orders in $\alpha_s$. Borel images of coefficient functions in this limit contain renormalon poles. Naive nonabelianization works surprisingly poorly for the coefficient functions considered here. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Sterile Neutrinos at MAPP in the B-L Model https://arxiv.org/abs/2311.01719 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2311.01719v2 Announce Type: replace Abstract: The possibility of searching for right-handed neutrinos at the MoEDAL's Apparatus for Penetrating Particles (MAPP) detector is investigated in this work. In particular, pair-production of right-handed (RH) neutrinos $N$ from either a $B-L$ gauge boson $Z'$, as well as Standard Model (SM) $Z$ boson are considered. Under a no-background assumption, we show that the MAPP detector can be sensitive to active-sterile neutrino mixing strengths as low as $V_{\mu N}^2 \approx 10^{-12}$ for multiple choices of $m_N / m_{Z'}$ values, when taking the $B-L$ gauge coupling $g_{B-L} = 10^{-3}$ near its current limit. The SM $Z$ boson portal can reach a similar sensitivity, when the effective mixing between the $B-L$ and SM gauge boson is $\alpha \approx 0.002$. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Non-local nonstabiliserness in Gluon and Graviton Scattering https://arxiv.org/abs/2603.04148 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04148v1 Announce Type: cross Abstract: The property of non-stabiliserness, or ``magic'', is of interest in quantum computing due to its role in developing fault-tolerant quantum algorithms with genuine computational advantage over classical counterparts. There has been much interest in quantifying magic in various physical systems, in order to probe how to produce and enhance it. The production of magic has previously been quantified in gluon and graviton scattering, in the so-called helicity basis relating particle spins with momentum directions. For a basis-independent statement, one should instead use the recently developed concept of non-local non-stabiliserness, and our aim in this paper is to derive how this varies for gluon and graviton scattering processes. Our results show that, for many initial states, including those produced with polarised beams, the helicity basis coincides with a basis in which the non-local magic is manifest, providing a physical motivation for using the helicity basis to study quantum information quantities. However, this property breaks upon adding additional operators to the Yang-Mills Lagrangian, as would be the case in new physics scenarios. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) An algorithm towards $\varepsilon$-factorising Feynman Integrals https://arxiv.org/abs/2603.03649 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03649v1 Announce Type: cross Abstract: In this talk, we use several examples to elaborate on how a recently proposed algorithm can turn non-trivial Feynman integrals into an $\varepsilon $-factorised manner, regardless of their hidden geometric essence. In particular, some extra details about three-loop banana integrals with unequal-mass configuration are provided. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) A framework for missing-energy searches with anomalous light vectors https://arxiv.org/abs/2603.04394 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04394v1 Announce Type: new Abstract: We study light spin-1 gauge bosons coupled to electroweak-anomalous currents. For generic charge assignments, anomaly cancellation requires new fermions (anomalons) that are chiral under the new abelian symmetry and carry electroweak charges. If their masses arise from the breaking of the new gauge symmetry, integrating them out generates Wess-Zumino interactions fixed by mixed-anomaly matching, providing the infrared description of the theory. We classify minimal anomalon spectra, derive the corresponding effective interactions, and combine experimental constraints with finite-naturalness considerations to bound the UV completion scale. Motivated by recent NA62 and Belle II results, we then develop a unified phenomenological framework for the missing-energy signatures of these anomalous light vectors, focusing on scenarios where the new vector decays predominantly into neutrinos so that the leading probes are rare processes with invisible final states. As applications, we survey current and projected searches across flavour and electroweak observables, including $K\to\pi E_{\rm miss}$, $B\to K^{(*)}E_{\rm miss}$, and $Z\to\gamma E_{\rm miss}$, and discuss their interplay with direct searches for anomalons. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Quantum Kinetic Theory for Quantum Chromodynamics https://arxiv.org/abs/2603.04263 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04263v1 Announce Type: new Abstract: We develop a quantum kinetic theory for QCD, which incorporates all leading order collision terms. At lowest order in gradient expansion, it reproduces the spin-averaged Boltzmann equation with both elastic and inelastic collisions. At next order in gradient expansion, the solution to the quantum kinetic equations give spin polarization of on-shell quarks and gluons in quark-gluon plasma when the gradients are of hydrodynamic ones. A power counting in the coupling shows the spin polarization behaves differently in vortical and non-vortical gradients: the former is free of collisional contribution to leading order, while the latter contains a collisional contribution at parametrically the same order as the free theory counterpart. We also find the inelastic collision in a spin basis provides a possible mechanism for conversion between spin and orbital angular momentum. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Nuclear $\mu-e$ conversion via Lorentz and CPT violation https://arxiv.org/abs/2603.04171 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04171v1 Announce Type: new Abstract: One of the three common experimental channels searching for charged lepton flavor violation (CLFV) via $\mu-e$ conversion involves first capturing the muon on a nuclear target. This channel provides a unique opportunity to constrain four-point quark-lepton operators that may contribute to CLFV, in addition to the electromagnetic operators that can also be accessed in the other channels. We investigate the leading Lorentz- and CPT-violating contributions for nuclear $\mu-e$ conversion experiments within the Standard-Model Extension and obtain the first bounds on the relevant quark-lepton operators using the results of the SINDRUM II experiment; we also consider possibilities for improved constraints from upcoming experiments. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Features of Spacetime-Symmetry Breaking and the Standard-Model Extension in Riemann-Cartan Geometry https://arxiv.org/abs/2603.04079 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04079v1 Announce Type: new Abstract: For over two decades, the gravity sector of the Standard-Model Extension (SME) has served as a phenomenological framework for testing spacetime symmetry breaking in the presence of gravity. During this time, various theoretical features have been examined in greater detail and some refinements have been made. In particular, differences between spontaneous and explicit breaking of diffeomorphisms, local translations, and local Lorentz transformations in Riemann-Cartan geometry, as well as their corresponding consistency issues with geometric and mathematical identities, have been probed more deeply. This has led to a modified version of the SME being developed that is suitable for investigating explicit breaking in gravity theories, which can be used as well to search for new geometries that go beyond Riemann-Cartan. A selective overview of some of these features is presented here. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) NNLO DGLAP splitting functions from collinear matching of TMDs https://arxiv.org/abs/2603.04039 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04039v1 Announce Type: new Abstract: We report a complete computation of next-to-next-to-leading order (NNLO) helicity and transversity Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) splitting functions, in both space-like and time-like kinematics. These results are obtained from the next-to-next-to-next-to-leading order (N$^3$LO) twist-2 matching of polarized transverse-momentum-dependent (TMD) parton distribution and fragmentation functions, including helicity, quark transversity, and linearly polarized gluons. We compare our results with existing calculations in the literature and discuss both agreements and discrepancies. Our results provide all perturbative ingredients required for the computation of N$^3$LO differential cross sections below the resolution scale $q_{T\mathrm{cut}}$ in transverse-momentum subtraction and enable next-to-next-to-next-to-next-to-leading logarithmic (N$^4$LL) resummation of $q_T$ observables in the Sudakov region. We further determine the small-$x$ structure of the polarized matching coefficients through N$^3$LO. These fixed-order results furnish the data for future small-$x$ resummation in polarized TMD factorization, where high-energy logarithms and Sudakov logarithms become simultaneously relevant. Establishing a consistent joint treatment of polarized small-$x$ evolution and transverse-momentum resummation remains an important open direction toward uniform precision in spin-dependent phenomenology. Our results provide essential theoretical input for precision spin physics at the forthcoming Electron-Ion Collider. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Weak Interaction Contribution to the Muonium Hyperfine Structure in the Standard Model https://arxiv.org/abs/2603.04026 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04026v1 Announce Type: new Abstract: The contribution of the weak interaction to the hyperfine splitting of the ground state of muonium is investigated. The amplitudes of the one- and two-quantum exchange determined by the Z and W bosons are calculated. One-loop corrections in the photon and Z boson propagators and their contribution to the hyperfine structure of the spectrum are obtained. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Leptogenesis from the Dirac CP-violating phase in the minimal left-right symmetric model https://arxiv.org/abs/2603.03874 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03874v1 Announce Type: new Abstract: Leptogenesis from low-energy CP violation provides a vital link between neutrino physics and the observed baryon asymmetry of the universe. However, this connection is typically obscured by unknown high-energy parameters. In this work, we investigate thermal leptogenesis in the Minimal Left-Right Symmetric Model with generalized parity as the left-right symmetry, where the hermiticity of the Dirac neutrino coupling allows the right-handed mixing matrix $V_\mathrm{R}$ to be determined with minimal assumptions. We show that for a real $V_\mathrm{R}$, these conditions favor CP-conserving Majorana phases, leaving the Dirac CP-violating phase ($\delta$) as the sole source of asymmetry. By numerically exploring all four leptogenesis scenarios, we demonstrate that $\delta$ alone can generate the observed baryon asymmetry with the correct sign within specific regions of the parameter space. The results exhibit a high sensitivity to the neutrino mass ordering and the lightest neutrino mass, providing a stringent, testable framework for future experimental measurements of the CP phase and neutrino mass scale. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Understanding the Structure of Doubly-Heavy Tetraquarks based on the Diquark Model https://arxiv.org/abs/2603.03764 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03764v1 Announce Type: new Abstract: We investigate the $T_{cc}$ tetraquark, treating it as a bound state of a heavy diquark and a light antidiquark. Using the Silvestre-Brac potential and solving the Schr\"odinger equation via the Gaussian Expansion Method, we find that the excitation energy between the heavy diquark and light antidiquark is unexpectedly larger than that between the two light anti-quarks within the anti-diquark -- contrary to the naive expectation where the former is smaller than the latter. We trace this inversion of the mass hierarchy to the centrifugal force acting on the light degree of freedom. Applying the same framework to other systems ($T_{bb}, \Lambda_b, \Lambda_c$) yields qualitatively identical behavior, demonstrating the robustness of the mechanism. These results provide new insights into diquark dynamics and the mass structure of exotic hadrons. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Method of regions for dual conformal integrals https://arxiv.org/abs/2603.03728 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03728v1 Announce Type: new Abstract: In this contribution, we present a recently introduced approach [BorkLeeOnishchenko2025] to the calculation of slightly off-shell dual conformal integrals based on the method of regions with regularization preserving dual conformal invariance (DCI). Unlike conventional dimensional regularization, which breaks DCI, our approach uses a combination of dimensional and analytic regularizations specifically designed to retain DCI throughout the calculation. Our approach drastically simplifies the computation of slightly off-shell dual conformal integrals. For the two-loop five-point DCI integrals we find that with DCI-preserving regularization, the contributions of all regions can be expressed in terms of $\Gamma$-functions, resulting in a remarkably compact final expression in terms of logarithms of cross-ratios only. This is in sharp contrast to conventional approach which yields complex polylogarithmic expressions [Belitsky&Smirnov2025]. We argue that a similar approach might be useful also for non-DCI integrals. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Searching for ALP Lepton Flavor Violation via ALP Decays at the LHC https://arxiv.org/abs/2603.03647 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03647v1 Announce Type: new Abstract: In the ALP model, lepton flavor violation (LFV) can arise from off-diagonal ALP-lepton couplings ($g_{a\ell_i\ell_j}$), which are absent in the Standard Model. We focus on ALP production via gluon fusion ($pp \to a$) at the Large Hadron Collider (LHC), which dominates the ALP mass range of 5-1000 GeV due to its high cross section and manageable backgrounds. We are interested in the decay of an axion into an electron and a muon, two oppositely charged leptons of different flavors. After background suppression, we obtain the sensitivity to ALP in this mass range, finding significantly improved limits for $5 < m_a < 1000$ GeV, where SM backgrounds are suppressed. Our research is complementary with relevant studies. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Emergent axion and Higgs boson from strong dynamics https://arxiv.org/abs/2603.03449 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03449v1 Announce Type: new Abstract: We propose a unified model that simultaneously addresses the hierarchy problem and the strong CP problem by considering the most simple fundamental composite Higgs setup and showing that it can feature a viable emergent axion that could be accessible at collider experiments. To maintain a low decay constant, and therefore address the hierarchy problem, while simultaneously avoiding experimental bounds on the axion couplings, we increase the axion mass via additional small instanton contributions coming from a new hidden gauge sector with a confinement scale larger than $\Lambda_{\text{QCD}}$. Specifically, the axion will be identified with the CP-odd scalar singlet contained in the $SU(4)/Sp(4)$ coset of the minimal fundamental composite Higgs model. Both the SM color group and the additional hidden sector group are then embedded into a larger non-Abelian \textit{grandcolor} group, such that the topological angles of the two sectors are guaranteed to agree at tree-level. Beyond that, we show that radiative corrections and other CP-violating sources can be controlled. After examining the field content and the gauge structure of the model, we analyze the pNGB spectrum, potential, and couplings, as well as the resulting phenomenology. We focus in particular on the axion potential, to understand under which conditions the CP-odd scalar singlet can solve the strong CP problem while maintaining a naturally low compositeness scale, identifying interesting viable parameter space for an axion in the GeV range. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Unitarity bounds and sum rules in the SMEFT https://arxiv.org/abs/2603.03423 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03423v1 Announce Type: new Abstract: We present a comprehensive reassessment of perturbative unitarity bounds in the dimension-six Standard Model Effective Field Theory, exploiting a new formalism based on spinor-helicity techniques to derive partial-wave unitarity bounds for generic $N \to M$ scattering amplitudes. We find that, in several cases, these theoretical constraints are already competitive with, or even stronger than, the corresponding experimental bounds for energy scales above a few TeV. This is especially the case for four-fermion operators under realistic flavor assumptions, where unitarity bounds can be further strengthened by exploiting sum rules. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Radius-Flow Entanglement in Hadron States and Gravitational Form Factors https://arxiv.org/abs/2603.03064 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03064v2 Announce Type: replace-cross Abstract: We propose a lattice-ready entanglement observable for QCD hadrons: the vacuum-subtracted radius flow of the ball R\'enyi entropy, $\mathfrak{s}_n(R;h)\equiv R\,\partial_R\Delta S_n(B_R;h)$, defined via the Euclidean replica cut-and-glue construction in a rest-frame momentum-projected one-hadron state, with spin averaging performed at the level of the final flow. In the continuum, varying $R$ at fixed shape is equivalent to a Weyl rescaling, so the flow is trace selected and admits a surface-plus-remainder organization on the entangling sphere. We use this to formulate a lattice stability test of boundary dominance: fit the measured flow on local $R$ windows to a low-curvature remainder plus a small template basis built from hadronic gravitational form factors (GFFs). The two endpoint templates are the spin-0/trace shape $\mathfrak{t}_h^{(0)}(R)=R^3\rho_S(R)$ constructed from $A^S(t)$ and a spin-2/TT proxy $\mathfrak{t}_h^{(2)}(R)=R^3\rho_A(R)$ constructed from $A(t)$, together with the mixed family $\mathfrak{t}_h^{\rm mix}(R;c_0,c_2)=c_0\mathfrak{t}_h^{(0)}(R)+c_2\mathfrak{t}_h^{(2)}(R)$. A soft-wall AdS/QCD appendix shows that the pole-subtracted integrated trace--energy correlator closes on this same $\{A^S,A\}$ basis and supplies a model-dependent benchmark ratio for $c_0/c_2$; for lattice comparison the coefficients are left free and extracted from data. For representative nucleon dipole inputs, the pure endpoints predict distinct single-extremum scales, $R_{\rm EE}^{(0)}\sim0.84~\mathrm{fm}$ and $R_{\rm EE}^{(2)}\sim0.43~\mathrm{fm}$, enabling discrimination among scalar control, spin-2 control, and genuine mixing through the turning-point location, the sign change of the slope across it, and the fitted ratio of template weights. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Trigonometric continuous-variable gates and hybrid quantum simulations of the sine-Gordon model https://arxiv.org/abs/2512.19582 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2512.19582v2 Announce Type: replace-cross Abstract: Hybrid qubit-qumode quantum computing platforms provide a natural setting for simulating interacting bosonic quantum field theories. However, existing continuous-variable gate constructions rely predominantly on polynomial functions of canonical quadratures. In this work, we introduce a complementary universality paradigm based on trigonometric continuous-variable gates, which enable a Fourier-like representation of bosonic operators and are particularly well suited for periodic and non-perturbative interactions. We present a deterministic ancilla-based method for implementing unitary and non-unitary trigonometric gates whose arguments are arbitrary Hermitian functions of qumode quadratures. As a concrete application, we develop a hybrid qubit-qumode quantum simulation of the lattice sine-Gordon model. Using these gates, we prepare ground states via quantum imaginary-time evolution, simulate real-time dynamics, compute time-dependent vertex two-point correlation functions, and extract quantum kink profiles under topological boundary conditions. Our results demonstrate that trigonometric continuous-variable gates provide a physically natural framework for simulating interacting field theories on near-term hybrid quantum hardware, while establishing a parallel route to universality beyond polynomial gate constructions. We expect that the trigonometric gates introduced here to find broader applications, including quantum simulations of condensed matter systems, quantum chemistry, and biological models. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Tensor Renormalization Group Calculations of Partition-Function Ratios https://arxiv.org/abs/2512.03395 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2512.03395v2 Announce Type: replace-cross Abstract: The behavior of dimensionless quantities defined as ratios of partition functions is analyzed to investigate phase transitions and critical phenomena. At criticality, the universal values of these ratios can be predicted from conformal field theory (CFT) through the modular-invariant partition functions on a torus. We perform numerical calculations using the bond-weighted tensor renormalization group for three two-dimensional models belonging to different universality classes: the Ising model, the three-state Potts model, and the four-state Potts model. The partition-function ratios obey the same finite-size scaling form as the Binder parameter, and their critical values agree well with the universal values predicted by CFT. In the four-state Potts model, we observe logarithmic corrections in the system-size dependence of these ratios. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Beyond Leading Logarithms in $g_V$: The Semileptonic Weak Hamiltonian at $\mathcal{O}(\alpha\,\alpha_s^2)$ https://arxiv.org/abs/2510.27648 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2510.27648v2 Announce Type: replace-cross Abstract: We present the first next-to-leading-logarithmic QCD analysis of the electromagnetic corrections to the semileptonic weak Hamiltonian, including the mixed $\mathcal{O}(\alpha\,\alpha_s^2)$ corrections to the vector coupling $g_V$. The analysis combines the evaluation of three-loop anomalous dimensions and two-loop matching corrections with a consistent factorization of short-distance QCD effects. The latter is implemented through a scheme change based on a $d$-dimensional operator product expansion performed inside the loop integrals. The resulting renormalization-group--improved expression for the radiative correction $\Delta^V_R = 2.436(16)\%$ can be systematically refined using input from lattice QCD and perturbation theory and improves the consistency of first-row CKM unitarity tests. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Committing to Bubbles: Finding the Critical Configuration on the Lattice https://arxiv.org/abs/2509.22057 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2509.22057v2 Announce Type: replace-cross Abstract: The nucleation of bubbles in first-order phase transitions is traditionally characterised by the critical bubble: defined as the saddle-point solution of the Euclidean action that separates collapsing from expanding field configurations. While this picture is exact in the noiseless, zero-temperature limit, thermal fluctuations introduces stochasticity which can influence the behaviour of the field configuration. In this work, we develop a purely statistical criterion for identifying the critical bubble by leveraging the concept of the ``committor'' probability: the likelihood that a given local field configuration evolves to the true vacuum before returning to the false vacuum. Using ensembles of lattice simulations with controlled thermal noise, we extract the committor probability during the evolution of a bubble from sub- to super-criticality. We find this approach to be robust, accounts for finite-temperature effects, and allows independent verification of bounce-based predictions. To demonstrate this, we compare the average profile obtained via the committor probability method to standard theory for a given model and find strong agreement, particularly at the core of the bubble. Importantly, we also observe that the behaviour of the committor probability with time is smooth and well defined. This method establishes a robust, simulation-driven framework for studying nucleation dynamics in thermal field theories and may be especially applicable in cases where analytical control might be limited. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Field digitization scaling in a $\mathbb{Z}_N \subset U(1)$ symmetric model https://arxiv.org/abs/2507.22984 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2507.22984v2 Announce Type: replace-cross Abstract: The simulation of quantum field theories, both classical and quantum, requires regularization of infinitely many degrees of freedom. However, in the context of field digitization (FD) -- a truncation of the local fields to $N$ discrete values -- a comprehensive framework to obtain continuum results is currently missing. Here, we propose to analyze FD by interpreting the parameter $N$ as a coupling in the renormalization group (RG) sense. As a first example, we investigate the two-dimensional classical $N$-state clock model as a $\mathbb{Z}_N$ FD of the $U(1)$-symmetric $XY$-model. Using effective field theory, we employ the RG to derive generalized scaling hypotheses involving the FD parameter $N$, which allows us to relate data obtained for different $N$-regularized models in a procedure that we term $\textit{field digitization scaling}$ (FDS). Using numerical tensor-network calculations at finite bond dimension $\chi$, we further uncover an unconventional universal crossover around a low-temperature phase transition induced by finite $N$, demonstrating that FDS can be extended to describe the interplay of $\chi$ and $N$. Finally, we analytically prove that our calculations for the 2D classical-statistical $\mathbb{Z}_N$ clock model are directly related to the quantum physics in the ground state of a (2+1)D $\mathbb{Z}_N$ lattice gauge theory which serves as a FD of compact quantum electrodynamics. Our study thus paves the way for applications of FDS to quantum simulations of more complex models in higher spatial dimensions, where it could serve as a tool to analyze the continuum limit of digitized quantum field theories. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) A Machine Learning Approach for Lattice Gauge Fixing https://arxiv.org/abs/2602.23731 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2602.23731v2 Announce Type: replace Abstract: Gauge fixing is an essential step in lattice QCD calculations, particularly for studying gauge-dependent observables. Traditional iterative algorithms are computationally expensive and often suffer from critical slowing down and scaling bottlenecks on large lattices. We present a novel machine learning framework for lattice gauge fixing, where Wilson lines are utilized to construct gauge transformation matrices within a convolutional neural network. The model parameters are optimized via backpropagation, and we introduce a hybrid strategy that combines a neural-network-based transformation with subsequent iterative methods. Preliminary tests on SU(3) gauge theory ensembles for Coulomb gauge demonstrate the potential of this approach to improve the efficiency of lattice gauge fixing. Furthermore, we show that the model exhibits lattice size transferability, where parameters optimized on smaller lattices remain effective for larger volumes without additional training. This framework provides a scalable path toward mitigating critical slowing down in high-precision gauge fixing. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Understanding the approach to thermalization from the eigenspectrum of non-Abelian gauge theories https://arxiv.org/abs/2407.09253 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2407.09253v2 Announce Type: replace Abstract: We study some interesting aspects of the spectral properties of SU(3) gauge theory, both with and without dynamical quarks (QCD) at thermal equilibrium using lattice gauge theory techniques. By calculating the eigenstates of a massless overlap Dirac operator on the gauge configurations, we implement a gauge-invariant method to study spectral properties of non-Abelian gauge theories. We have unambiguously categorized Dirac eigenvalues into different regimes based on a quantity defined in terms of the ratios of nearest neighbor spacings. While majority of these eigenstates below the magnetic scale are similar to those of random matrices belonging to the Gaussian Unitary ensemble at temperatures much higher than the chiral crossover transition in QCD, a few among them start to become prominent only near the crossover. These form fractal-like clusters with the median value for their fractal dimensions hinting at the universality class of the chiral transition in QCD. We further demonstrate that momentum modes below the magnetic scale in a particular non-equilibrium state of QCD are classically chaotic and estimate an upper bound on the thermalization time $\sim 1.44$ fm/c by matching this magnetic scale with that of a thermal state at $\sim 600$ MeV. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Quantum error mitigation by hierarchy-informed sampling: chiral dynamics in the Schwinger model https://arxiv.org/abs/2603.04339 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04339v1 Announce Type: cross Abstract: Quantum simulations on current NISQ hardware are limited by its noisy nature, making efficient quantum error mitigation methods highly demanded. In this paper we introduce a novel mitigation scheme, applicable to arbitrary quantum simulations of time-dependent Hamiltonian dynamics on NISQ devices. The scheme uses a polynomial subset of extended qubit Bogoliubov-Born-Green-Kirkwood-Yvon (BBGKY) hierarchy equations as a sampling criterion of possible mitigated candidates for the quantum observables. We show that for favorable Hamiltonians the polynomial subset of BBGKY hierarchy equations leads to a polynomial overhead in both classical and quantum resources. We employ the method to mitigate simulations of the chiral magnetic effect (CME), a chiral feature of the Schwinger model. We empirically show the effectiveness of our scheme at recovering the real-time dynamics of the CME from noisy quantum simulations of the Schwinger model, for a range of different parameter values of the model. We numerically demonstrate a systematic reduction of quantum noise, together with an increasing noise reduction capability as the amount of BBGKY constraints grows. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Topological observables and domain wall tension from finite temperature chiral perturbation theory https://arxiv.org/abs/2603.04116 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04116v1 Announce Type: cross Abstract: Within the framework of SU(2) chiral perturbation theory, we derive the general solution of the QCD $\theta$-vacuum for an arbitrary vacuum phase, explicitly incorporating isospin-breaking effects from the light quark mass difference, and compute the temperature dependence of the topological susceptibility, higher-order cumulants, and the domain wall tension up to next-to-leading order. We find that the topological susceptibility agrees with lattice data at low temperatures but deviates at higher temperatures as expected from the breakdown of the chiral expansion; moreover, we demonstrate that the normalized fourth-order cumulant and the domain wall tension decrease monotonically with increasing temperature, while the normalized sixth-order cumulant exhibits the opposite behavior. These results extend earlier analyses by showing how isospin breaking reshapes the full hierarchy of topological charge cumulants and the dynamics of $\theta$-vacuum domain walls, thereby offering new theoretical input on the $\theta$-vacuum properties, which are relevant for axion-related effective theories in hot QCD matter. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Enhancing Variational Quantum Eigensolvers for SU(2) Lattice Gauge Theory via Systematic State Preparation https://arxiv.org/abs/2603.03799 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03799v1 Announce Type: cross Abstract: Computing the vacuum and energy spectrum in non-Abelian, interacting lattice gauge theories remains an open challenge, in part because approximating the continuum limit requires large lattices and huge Hilbert spaces. To address this difficulty with near-term quantum computing devices, we adapt the variational quantum eigensolver to non-Abelian gauge theories. We outline scaling advantages when using a spin-network basis to simulate the gauge-invariant Hilbert space and develop a systematic state preparation ansatz that creates gauge-invariant excitations while alleviating the barren plateau problem. We illustrate our method in the context of SU(2) Yang-Mills theory by testing it on a minimal toy model consisting of a single vertex in 3+1 dimensions. In this toy model, simulations allow us to investigate the impact of noise expected in current quantum devices. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Impact of Dynamical Charm Quark and Mixed Action Effect on Light Hadron Masses and Decay Constants https://arxiv.org/abs/2603.04230 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04230v1 Announce Type: new Abstract: We investigate the impact of including a dynamical charm quark on the properties of light hadrons. Our study uses gauge ensembles generated with the tadpole-improved Symanzik gauge action, comparing 2+1+1 flavor (HISQ fermion) ensembles at four lattice spacings to 2+1 flavor (clover fermion) ensembles at six lattice spacings. For the light and strange flavor observables, we employ the same tadpole-improved clover fermion action. From numerical results for light and strange quark masses, pion and kaon decay constants, and $\Omega$ baryon masses, we find that the values obtained after continuum, chiral, and infinite-volume extrapolations are consistent within uncertainties. Even though the mixed action setup can introduce additional discretization effects, our calculation shows evidences that those effects can cancel with the discretization error in the unitary setup, resulting in better convergence in the continuum extrapolation. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Towards the time-like pion form factor beyond the elastic regime using domain-wall QCD https://arxiv.org/abs/2603.04094 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04094v1 Announce Type: new Abstract: In this work, we investigate the time-like pion form factor from lattice QCD in the isosymmetric limit, a quantity that plays an important role in understanding hadron physics with substantial phenomenological applications. This observable can be calculated in the elastic region using the finite-volume approach, up to the first (four-particle) open channel. With the goal of accessing the exclusive two-pion form factor in the inelastic region, starting from a three-point correlator involving the vector current and two (temporally-displaced) pion interpolating operators, we examine the associated underlying spectral density and calculate the form factor using a formalism based on the LSZ reduction. A preliminary analysis on one ensemble generated by the RBC/UKQCD collaboration using domain-wall fermions is presented. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) BMW/DMZ calculation of the hadronic vacuum polarisation for the muon magnetic moment https://arxiv.org/abs/2603.03835 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03835v1 Announce Type: new Abstract: For twenty years, a persistent discrepancy between experimental measurements and theoretical calculations of the muon anomalous magnetic moment have provided tantalising hints of new physics. In recent years, improvements to the experimental precision have appeared to make the tension stronger and stronger. However, at the same time, our lattice calculation overturned the theoretical consensus, completely eliminating the tension. I will present the latest results from the Budapest-Marseille-Wuppertal (BMW) and DMZ collaborations, with a hybrid determination of the hadronic vacuum polarisation contribution to a precision of 0.45% High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Lattice extraction of the Collins-Soper kernel using the auxiliary field representation of the Wilson line https://arxiv.org/abs/2603.03814 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03814v1 Announce Type: new Abstract: The Collins-Soper (CS) kernel may be obtained through the TMD soft function by formulating the Wilson line in terms of 1-dimensional auxiliary fermion fields on the lattice. Our computation takes place in the region of the lattice that corresponds to the "spacelike" region in Minkowski space, i.e., Collins' scheme. We explore two methods for obtaining the CS kernel. The "ratio method"; which would allow us to obtain the soft function as well as the CS kernel. And the "double ratio"; which allows us to achieve a high degree of statistical precision, but only produces the CS kernel. The matching of our result to Minkowski space is achieved through the mapping of the complex auxiliary field directional vector to the Wilson line rapidity. We present a preliminary extraction of the CS kernel using the "double ratio", and discuss the methodology employed. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Quantum anomaly for benchmarking quantum computing https://arxiv.org/abs/2603.03697 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03697v1 Announce Type: new Abstract: Given the rapid advances in quantum computing hardware, establishing systematic strategies for verifying the correctness of quantum computations has become increasingly important. Exploiting the fact that the axial anomaly in gauge theories is exact to all orders in perturbation theory, we propose the axial anomaly as a nontrivial benchmark for quantum simulations of lattice gauge theories. We simulate anomalous axial-charge production in ${\mathbb Z}_N$ lattice gauge theories on the trapped-ion quantum computer ``Reimei''. After taking the U(1), infinitesimal time, and infinite volume limits, we successfully reproduce the anomaly coefficient within statistical uncertainties, even without error mitigation. Our results demonstrate that the axial anomaly can be simulated on current quantum computers and serves as a verification test of quantum computations. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Axial-vector molecules $\Upsilon B_{c}^{-}$ and $\eta_{b}B_{c}^{\ast-} $ https://arxiv.org/abs/2512.06513 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2512.06513v2 Announce Type: replace-cross Abstract: Axial-vector hadronic molecules $\mathcal{M}_{\mathrm{AV}}=\Upsilon B_{c}^{-} $ and $\widetilde{\mathcal{M}}_{\mathrm{AV}}=\eta_{b}B_{c}^{\ast -} $ with the quark content $bb \overline{b}\overline{c}$ are studied using QCD sum rule method. The spectroscopic parameters of these molecules are computed in the context of the two-point sum rule method. Predictions for their masses are identical to each other and confirm that they are structures unstable against dissociations to ordinary heavy mesons. We evaluate the width of the state $\mathcal{M}_{\mathrm{AV}}$ and assume that it is equal to that of $\widetilde{\mathcal{M}}_{\mathrm{AV}} $. To this end, we explore its dominant decay channels $\mathcal{M}_{\mathrm{AV}} \to \Upsilon B_{c}^{-} $ and $\mathcal{M}_{\mathrm{AV}} \to \eta_{b}B_{c}^{\ast -}$. There also are subleading modes of $\mathcal{M}_{\mathrm{AV}}$ generated due to annihilation of $\overline{b}b$ quarks. We consider decays of the molecule $\mathcal{M}_{\mathrm{AV}}$ to pairs of the mesons $B^{\ast -} \overline{D}^{0}$, $\overline{B}^{\ast 0} D^{-}$, $B^{-} \overline{D} ^{\ast 0}$, $\overline{B}^{0} D^{\ast -}$, $\overline{B}_{s}^{\ast 0} D_{s}^{-}$, and $\overline{B}_{s}^{0} D_{s}^{\ast -}$. To find strong couplings at the $\mathcal{M}_{\mathrm{AV}}$-meson-meson vertices which determine the partial widths of these processes, we apply QCD three-point sum rule approach. The mass $m=(15800 \pm 90)~\mathrm{MeV}$ and width $ \Gamma [\mathcal{M}_{\mathrm{AV}}]=(114 \pm 17)~ \mathrm{MeV}$ of the molecule $\mathcal{M}_{\mathrm{AV}}$ are useful for experimental studies of fully heavy molecular structures at ongoing and planning experiments. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Deriving a parton shower for jet thermalization in QCD plasmas https://arxiv.org/abs/2510.25837 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2510.25837v2 Announce Type: replace-cross Abstract: Jet quenching - the modification of high-energy jets in the quark-gluon plasma - has been extensively studied through weakly coupled scattering amplitudes embedded in parton-shower frameworks. These models, often combined with bulk hydrodynamic evolution, successfully describe a wide range of observables, though they typically rely on assumptions of rapid thermalization and simplified treatments of medium response. Parallel to these developments, jet thermalization has been investigated within the finite-temperature QCD effective kinetic theory, which provides our best microscopic understanding of equilibration in heavy-ion collisions. Early studies of linearized perturbations have highlighted both the promise and the limitations of current approaches, as existing MC implementations face challenges - particularly in the treatment of recoils and particle merging. Building on this foundation, we introduce a new parton-shower algorithm that exactly reproduces the dynamics of the linearized EKT, enabling a first-principles description of jet thermalization with proper inclusion of recoils, holes, quantum statistics, and merging processes. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) High Quality QCD Axion in the Standard Model https://arxiv.org/abs/2510.17370 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2510.17370v3 Announce Type: replace-cross Abstract: Although the axion is the most compelling solution to the strong CP problem, the ad hoc introduced global Peccei-Quinn symmetry suffers from a severe fine-tuning problem known as the quality problem. In this Letter, we show that the discrete gauge symmetry $\mathbb Z_4 \times \mathbb Z_3$ motivated from the internal structure of the Standard Model can naturally predict a high-quality axion, leading to a distinct and testable parameter space. Remarkably, this minimal framework simultaneously accounts for neutrino masses, baryon asymmetry, and dark matter. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Fair Universe Higgs Uncertainty Challenge https://arxiv.org/abs/2509.22247 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2509.22247v3 Announce Type: replace-cross Abstract: This competition in high-energy physics (HEP) and machine learning was the first to strongly emphasise uncertainties in $(H \rightarrow \tau^+ \tau^-)$ cross-section measurement. Participants were tasked with developing advanced analysis techniques capable of dealing with uncertainties in the input training data and providing credible confidence intervals. The accuracy of these intervals was evaluated using pseudo-experiments to assess correct coverage. The dataset is now published in Zenodo, and the winning submissions are fully documented. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Quantitative U/Th deposition and cleanliness control strategies in the JUNO site air https://arxiv.org/abs/2507.05759 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2507.05759v2 Announce Type: replace-cross Abstract: The Jiangmen Underground Neutrino Observatory (JUNO) employs a 20 kt liquid scintillator (LS) detector located 700 m underground. To meet its physics objectives, the LS must achieve an ultra-low $^{238}$U/$^{232}$Th content of 10$^{-17}$ g/g. Given that airborne dust exhibits radioactivity about 12 orders of magnitude higher, exceptional cleanliness is essential during on-site installation. The total permissible dust mass in the 20 kt LS is only about 8 mg. To attain this, the acrylic vessel interior must comply with class 1,000 cleanliness. Pre-filling water spray cleaning improves cleanliness by roughly two orders of magnitude, requiring the overall environment to be maintained between class 10,000 and 100,000. At JUNO, a cleanroom management system has been implemented across the 120,000 m$^3$ underground experimental hall. Since May 2022, continuous laser particle monitoring has consistently achieved an average cleanliness class of 74,000. Furthermore, we developed a method to directly measure $^{238}$U/$^{232}$Th deposition rates on detector surfaces. Using ICP-MS, sensitivity reaches sub-ppt levels ($<$10$^{-12}$ g/g), enabling effective cleanliness control and assessment of external contamination during detector construction. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) New bound on the vectorial axion-down-strange coupling from $K^+ \to \pi^+ \nu \bar \nu$ data https://arxiv.org/abs/2503.05865 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2503.05865v2 Announce Type: replace-cross Abstract: We reinterpret publicly available $K^+ \to \pi^+ \nu \bar{\nu}$ data collected by NA62 from 2016 to 2024 to constrain the fundamental vectorial coupling of the QCD axion to down and strange quarks. Using a fully reproducible likelihood analysis and a complete renormalization-group evolution of the axion couplings from the Peccei-Quinn (PQ) scale to the kaon scale, we translate the experimental limit into bounds on both the low-energy flavour-violating coupling and the fundamental UV parameters. In the generic regime where strong contributions dominate the decay amplitude, we obtain $|(F_V)_{sd}(\mu_K)| > 1.6 \times 10^{12}\,\text{GeV}$. The coexistence of parametrically suppressed weak contributions implies a second, conceptually distinct constraint: the fact that weak-amplitude dominance arises from highly tuned UV coupling configurations, translates into a conservative general lower limit on the PQ scale, $f_a > 4.9 \times 10^4\,\text{GeV}$. These results provide the strongest accelerator-based constraints on axion-induced $d \leftrightarrow s$ transitions and establish a robust lower bound on $f_a$, complementary to astrophysical limits. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Combination of ATLAS and CMS searches for Higgs boson pair production at $\sqrt{s} = 13$ TeV https://arxiv.org/abs/2602.23991 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2602.23991v2 Announce Type: replace Abstract: This Letter presents a combination of searches for Higgs boson pair (HH) production performed by the ATLAS and CMS Collaborations using proton-proton collision data sets recorded at $\sqrt{s} = 13$ TeV during the Large Hadron Collider Run 2, corresponding to integrated luminosities ranging between 126 and 140 $\mathrm{fb^{-1}}$. The upper limit at the 95% confidence level on the total HH signal strength, defined as the ratio of the measured cross section to the SM prediction, corresponds to 2.5, with an expected value of 1.7 (2.8) assuming the absence (presence) of the standard model (SM) HH signal. The strength of the HH signal is measured to be $0.8^{+0.9}_{-0.7}$ relative to the SM prediction. The observed significance is found to be 1.1 standard deviations whereas 1.3 are expected for the SM HH signal. Constraints are set on the Higgs boson trilinear self-coupling and on the couplings of two Higgs bosons to two vector bosons, both normalized to the SM predictions and denoted as $\kappa_\lambda$ and $\kappa_{2\mathrm{V}}$, respectively. The observed individual constraints at the 95% confidence level are $-0.71 < \kappa_\lambda < 6.1$ and $0.73 < \kappa_{2\mathrm{V}} < 1.3$, while the expected constraints assuming the presence of the SM HH signal are $-1.3 < \kappa_\lambda < 6.7$ and $0.66 < \kappa_{2\mathrm{V}} < 1.4$. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Irradiation Studies of TGC Electronics Components for the ATLAS Experiment at High-Luminosity LHC https://arxiv.org/abs/2603.04129 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04129v1 Announce Type: cross Abstract: This paper evaluates the radiation tolerance of commercial off-the-shelf (COTS) electronics components for use in the Thin Gap Chamber (TGC) frontend electronics of the ATLAS experiment at the High-Luminosity LHC (HL-LHC). The ATLAS experiment has accumulated more than 450 fb^-1 of data as of 2025. Its luminosity upgrade, the HL-LHC scheduled to begin operation in 2030, will deliver 3000-4000 fb^-1 over ten years and lead to substantially higher radiation levels in detector electronics. The radiation levels for the TGC frontend electronics are estimated to be 4.1-7.3 Gy in terms of Total Ionizing Dose (TID) and 1.1-2.2 x 10^11 n_1MeV cm^-2 in terms of Non-Ionizing Energy Loss (NIEL). To evaluate component suitability under these conditions, TID tests were conducted using Cobalt-60 gamma rays at Nagoya University, and NIEL tests were performed with the Tandem Accelerator at Kobe University. Various COTS components, including SFP+ optical transceivers, clock jitter cleaners, optical fibers, voltage references, operational amplifiers, analog-to-digital converters, digital-to-analog converters, SD cards, flash memories, and low-dropout regulators, were tested and evaluated against the required radiation levels. The results demonstrate that all evaluated components meet the TID and NIEL tolerance requirements for application in the TGC frontend electronics at the HL-LHC. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) The CMS ME0 Upgrade: Enhancing Forward Muon Reconstruction at the HL-LHC https://arxiv.org/abs/2603.04107 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04107v1 Announce Type: cross Abstract: The CMS muon system is undergoing substantial upgrades to meet the challenges of the High-Luminosity LHC (HL-LHC), including the installation of the new Muon Endcap 0 (ME0) detector. Large-scale production started in 2024. ME0 is a six-layer station designed to extend pseudo-rapidity coverage to |{\eta}| = 2.8 from the previous maximum of |{\eta}| = 2.4, enhancing sensitivity to forward physics processes. Each endcap will host 18 ME0 stacks, with each stack comprising six triple-layer gas electron multiplier (GEM) chambers. The system adds up to six additional hits per track, which significantly improves muon identification, spatial resolution, and robust track reconstruction at the first trigger level. Chamber production and quality control across multiple international sites ensure scalability and timely delivery. The ME0 design incorporates lessons learned from earlier GEM deployments, with improvements in electronics robustness, grounding, and segmentation to withstand high background rates and minimize damage from discharges. This contribution provides a comprehensive overview of the ME0 detector concept, assembly strategy, quality assurance procedures, current production status, and its pivotal role in strengthening CMS muon reconstruction during HL-LHC operations. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Interpretation of $\Omega(2012)$ as a $\Xi(1530)K$ molecular state https://arxiv.org/abs/2603.03976 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03976v1 Announce Type: cross Abstract: We investigate the mass and strong decay properties of the $\Omega(2012)$ resonance using QCD sum rules, assuming it to be an S-wave $\Xi(1530)K$ molecular pentaquark state with $IJ^{P} = 0\frac{3}{2}^{-}$. A unified interpolating current is constructed, and the two-point and three-point correlation functions are calculated up to dimension-10 condensates in the OPE series. The negative-parity contribution is isolated by employing parity-projected sum rules. The two-body strong decays to $\Xi^0 K^-$ and $\Xi^- K^0$ are studied via their three-point correlation functions. Our analysis yields a mass of $2.00 \pm 0.15~\mathrm{GeV}$ and a total two-body decay width of $\Gamma = 3.97^{+8.31}_{-1.92}~\mathrm{MeV}$ for the $\Xi(1530)K$ molecular state. The ratios of branching fractions are obtained as $\mathcal{R}^{\Xi^- K^0}_{\Xi^0 K^-} = 0.85$ and $\mathcal{R}^{\Xi \pi K}_{\Xi K} = 0.61$. These results are compatible well with the experimental data for the $\Omega(2012)$ and support its interpretation as a $\Xi(1530)K$ molecular pentaquark state. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Flavor in Ninths and a Discrete Gauge Origin of the QCD Axion https://arxiv.org/abs/2603.03631 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03631v1 Announce Type: cross Abstract: Quark and lepton hierarchies are organized by rational powers of a single parameter in units of one ninth. We show that this ``flavor in ninths'' structure points to a discrete $\mathbb{Z}_{18}$ gauge origin of Froggatt--Nielsen symmetry, whose $\mathbb{Z}_9$ subgroup controls the flavor lattice. Identifying the flavon with the Peccei--Quinn field, the same symmetry stabilizes the QCD axion, enforces $N_{\rm DW}=1$, and predicts $E/N=8/3$ (or $2$ with light higgsinos). The lowest Planck-suppressed operator appears at dimension eighteen, naturally solving the axion quality problem. For $f_a\sim(5$--$8)\times10^{11}$ GeV the axion accounts for dark matter and lies within near-term haloscope reach. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Improved Pion-Kaon Identification in Heavy-Ion Collisions with a Two-Dimensional Transformation https://arxiv.org/abs/2603.03353 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03353v1 Announce Type: cross Abstract: Accurate identification of charged pions and kaons is essential for precision measurements in relativistic heavy-ion collisions, but becomes increasingly challenging at intermediate and high transverse momentum due to the overlap between time-of-flight mass-square ($m^{2}$) and ionization energy loss ($n\sigma$) distributions. In this work, we present a two-dimensional shift and rotation method that exploits the correlated information between $m^{2}$ and $n\sigma$ to enhance particle identification performance. The method is validated using Au+Au collision events generated with the AMPT model, where detector response effects are incorporated through a data-driven smearing procedure tuned to reproduce the particle identification performance of the STAR experiment. The reconstructed pion and kaon transverse momentum distributions show excellent agreement with the AMPT input, maintaining a purity exceeding 98\% at high $p_T$ and extend the reliable identification range up to $p_T \approx$ 3 GeV/$c$. The extracted elliptic flow $v_2$ remains consistent with the input over the extended $p_T$ range, demonstrating that the proposed method provides a robust framework for high precision identified hadron measurements. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Atmospheric neutrino constraints on Lorentz invariance violation with the first six detection units of KM3NeT/ORCA https://arxiv.org/abs/2603.04264 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04264v1 Announce Type: new Abstract: Lorentz invariance is a fundamental symmetry underlying both the Standard Model of particle physics and General Relativity. Testing its validity provides a direct means of searching for new physics emerging near the Planck scale. A search for isotropic Lorentz invariance violation with 1.4 years of atmospheric neutrino data collected by a partial configuration of the KM3NeT/ORCA detector comprising six detection units is presented. No evidence for such violation is found; thus, competitive limits are set on a subset of isotropic Lorentz invariance violating coefficients, which complement and extend existing experimental constraints. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) $e^+e^- \rightarrow s\bar{s}$ at $\sqrt{s} = 250$ GeV at future linear colliders https://arxiv.org/abs/2603.04200 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04200v1 Announce Type: new Abstract: The forward--backward asymmetry ($A_{FB}$) in light-quark production is a sensitive probe of the electroweak sector and potential flavour-dependent BSM effects. We present a study of $e^+e^- \rightarrow s\bar{s}$ at $\sqrt{s}=250$ GeV at future linear colliders, using full ILD simulation and reconstruction tools for ILC and LCF@CERN. We assess the impact of particle identification on charge reconstruction and $A_{FB}$ extraction, considering software improvements using Comprehensive PID (CPID) for optimal $dE/dx$ usage, as well as hardware scenarios including cluster counting ($dN/dx$) and ideal TPC performance. Statistical precision gains are evaluated, with corrections for charge misidentification and acceptance applied. Results indicate that precise $A_{FB}^{s\bar{s}}$ measurements are feasible and that advanced PID is key to maximising sensitivity to electroweak and new-physics effects. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Searches in CMS for New Physics in Final States with Leptons https://arxiv.org/abs/2603.04150 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04150v1 Announce Type: new Abstract: Many new physics models, such as the Sequential Standard Model, Grand Unified Theories, models of extra dimensions, or models like leptoquarks or vector-like leptons, predict heavy mediators at the TeV energy scale. We present recent results of such searches in leptonic final states obtained using data recorded by the CMS experiment during Run-II of the LHC. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Experimental Advances on Light Baryon Spectroscopy at BESIII Experiment https://arxiv.org/abs/2603.04141 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04141v1 Announce Type: new Abstract: The BESIII experiment is currently the world's only electron-positron collider operating in the tau-charm physical energy region. Since starting data taking in 2009, BESIII has accumulated the world's largest data set in the center-of-mass energy range of 1.84-4.95 GeV, including approximately 10 billion $J/\psi$ events and 3 billion $\psi(3686)$ events, together with extensive data on open-charm hadron pair production near threshold regions. These unique datasets, characterized by high statistics and low background, provide unprecedented experimental conditions for studying light baryon spectroscopy. This article systematically reviews the progress made by BESIII in baryon spectroscopy, with a focus on recent breakthrough achievements, including the discovery of excited nucleon states, $\Lambda$ hyperon states, $\Sigma$ hyperon states, $\Xi$ hyperon states and $\Omega^{-}$ hyperon states. These results expand the spectrum of baryon excited states and provide crucial experimental support for understanding non-perturbative QCD and resolving the ``missing baryon resonances'' problem. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Precise measurement of the form factors in $D^0\rightarrow K^*(892)^-\ell^+\nu_{\ell}$ and observation of $D^0\rightarrow K_2^*(1430)^-\ell^+\nu_{\ell}$ https://arxiv.org/abs/2603.04136 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04136v1 Announce Type: new Abstract: We report a study of the semileptonic decays $D^0 \rightarrow \bar{K}^0\pi^-\ell^+\nu_{\ell}$ (where $\ell=e,~\mu$) based on a sample of $20.3~\mathrm{fb}^{-1}$ of $e^+e^-$ annihilation data collected at a center-of-mass energy of 3.773~GeV with the BESIII detector at the BEPCII collider. Based on an investigation of the decay dynamics in $D^0 \rightarrow \bar{K}^0\pi^-\ell^+\nu_{\ell}$ decays, a $\mathcal{D}-$wave component of $D^0\rightarrow K_2^*(1430)^-\ell^+\nu_{\ell}$ is observed for the first time with a statistical significance of $8.0\sigma$, in addition to the dominant $K^*(892)^-$ and $\mathcal{S}-$wave components. The $\mathcal{D}-$wave component is determined to account for $(0.092 \pm 0.028_{\rm stat} \pm 0.018_{\rm syst})\%$ of the total decay rate. The branching fractions of the dominant $K^*(892)^-$ components are measured as $\mathcal{B}(D^0\rightarrow K^{*}(892)^-e^+\nu_{e}) = (2.043 \pm 0.018_{\rm stat} \pm 0.012_{\rm syst})\%$ and $\mathcal{B}(D^0\rightarrow K^{*}(892)^-\mu^+\nu_{\mu}) = (1.964 \pm 0.018_{\rm stat} \pm 0.012_{\rm syst})\%$, which are the most precise measurements to date and represent significant improvements over the previous world averages. The hadronic form-factor parameters are measured to be $r_{V} = V(0)/A_1(0) = 1.444 \pm 0.026_{\rm stat} \pm 0.010_{\rm syst}$, $r_{2} = A_2(0)/A_1(0) = 0.752 \pm 0.020_{\rm stat} \pm 0.004_{\rm syst}$, and $A_1(0)=0.618\pm0.002_{\rm stat} \pm0.004_{\rm syst}$, where $V(0)$ is the vector form factor and $A_{1,2}(0)$ are the axial-vector form factors evaluated at $q^2=0$. This is the most precise determination of the form-factor parameters to date measured in a $D\rightarrow K^*(892)$ transition. In addition, we report the first model-independent measurement of the $\mathcal{S}-$wave phase shift in the hadronic $\bar{K}^0\pi^-$ system. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) End-to-end event reconstruction for precision physics at future colliders https://arxiv.org/abs/2603.04084 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04084v1 Announce Type: new Abstract: Future collider experiments require unprecedented precision in measurements of Higgs, electroweak, and flavour observables, placing stringent demands on event reconstruction. The achievable precision on Higgs couplings scales directly with the resolution on visible final state particles and their invariant masses. Current particle flow algorithms rely on detector specific clustering, limiting flexibility during detector design. Here we present an end-to-end global event reconstruction approach that maps charged particle tracks and calorimeter and muon hits directly to particle level objects. The method combines geometric algebra transformer networks with object condensation based clustering, followed by dedicated networks for particle identification and energy regression. Our approach is benchmarked on fully simulated electron positron collisions at FCC-ee using the CLD detector concept. It outperforms the state-of-the-art rule-based algorithm by 10--20\% in relative reconstruction efficiency, achieves up to two orders of magnitude reduction in fake-particle rates for charged hadrons, and improves visible energy and invariant mass resolution by 22\%. By decoupling reconstruction performance from detector-specific tuning, this framework enables rapid iteration during the detector design phase of future collider experiments. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Imaging baryon number density within the proton https://arxiv.org/abs/2603.03730 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03730v1 Announce Type: new Abstract: The spatial extent of the proton is a key factor in nuclear physics. Different measurement techniques probe different aspects of the proton, yielding different radii. The mass and charge radii depend on the parton and quark distributions respectively, while the mechanical radius depends on the mass/energy distribution. Here, we probe the spatial distribution of a new proton characteristic, studying the distribution of baryon number within the proton. We investigate the baryon number distribution by studying four exclusive meson production channels arising from photon-proton collisions ($\gamma p \rightarrow p \rho^0$, $\gamma p \rightarrow p \omega$, $\gamma p \rightarrow n \pi^+$, and $\gamma p \rightarrow p \pi^0$). The two-dimensional transverse sizes of the interacting systems are extracted by analyzing the transverse momentum, $p_T$, dependence of the meson production cross section, using Fourier-Bessel transformations. We find that baryon number is confined to a transverse radius of $0.33 - 0.53$~fm. In comparison, the transverse radius of the proton charge and mass distributions are considerably larger, at least 0.67~fm. The baryon number is concentrated in the center of the proton. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Measurement of angular correlations inside jets induced by gluon polarization in proton-proton collisions at $\sqrt{s}$ = 13.6 TeV https://arxiv.org/abs/2603.03689 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03689v1 Announce Type: new Abstract: A study of angular correlations inside jets induced by gluon polarization is performed using proton-proton collisions at a center-of-mass energy of $\sqrt{s}$ = 13.6 TeV. The data correspond to an integrated luminosity of 34.7 fb$^{-1}$, collected in 2022 with the CMS detector at the LHC. The details of the parton shower are investigated using jets reconstructed with the anti-$k_\mathrm{T}$ algorithm and subsequently declustered with the Cambridge$-$Aachen algorithm. A novel analysis technique is developed to identify characteristic features of the jet substructure and to select intermediate gluon splittings into quark-antiquark pairs. An observable sensitive to gluon polarization in the parton shower is measured and compared with PYTHIA 8 and HERWIG 7 model predictions, with and without angular correlations induced by the gluon spin. The results are consistent with models that incorporate gluon polarization and strongly disfavor those that neglect them. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Single-minus graviton tree amplitudes are nonzero https://arxiv.org/abs/2603.04330 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04330v1 Announce Type: cross Abstract: Single-minus tree-level $n$-graviton scattering amplitudes are revisited. Often presumed to vanish, they are shown here to be nonvanishing for certain "half-collinear" configurations existing in Klein space or for complexified momenta. A Berends-Giele recursion relation for these amplitudes is derived and solved in a form involving a sum over trees. In a restricted kinematic decay region, this solution simplifies significantly to an $(n{-}2)$-fold product of soft factors. It is further shown in this region that, combined with suitable analyticity assumptions, the $n$-graviton amplitude is generated by a recursive $\mathcal{L}w_{1+\infty}$ Ward identity with the three-graviton amplitude as a seed. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Resumming Spinning Black Hole Dynamics at Third Post-Minkowskian Order https://arxiv.org/abs/2603.04214 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04214v1 Announce Type: cross Abstract: We investigate the relativistic scattering of spinning black holes using modern amplitude methods within a heavy-mass effective field theory formalism at third post-Minkowskian order. Using a systematic self-force expansion up to first order in the mass ratio, the gravitational amplitude and the associated eikonal-like phase are computed for a spin-aligned binary system comprising a heavy and a light black hole up to fifth order in the total spin and up to quadratic order in the spin of the light black hole. We also consider the resummation of the heavy black hole's spin in both the probe limit and the radiation-reaction sector, and verify that the resulting phase displays the characteristic ring singularity features associated with the Kerr metric. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Observational Indistinguishability and the Beginning of the Universe https://arxiv.org/abs/2603.04159 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04159v1 Announce Type: cross Abstract: Can we infer whether all of physical reality began to exist? Several novel results are offered suggesting a negative verdict. First, a common strategy for defending a cosmic beginning involves showing that individual beginningless cosmological models are implausible. This strategy is shown to make an elementary error in confirmation theory. Second, two necessary (but not necessarily sufficient) conditions are offered for a cosmic beginning. Third, three extensions are offered to the Malament-Manchak theorems. The three extensions show that in almost all classical spacetimes, observers cannot collect sufficient data to determine whether the application conditions for the classic singularity theorems are satisfied or whether their spacetime satisfies the two necessary conditions for a cosmic beginning. Lastly, a reply is offered to the objection that the skeptical consequences of the three extensions can be overcome with induction. Importantly, all past singular dust FLRW spacetimes have observationally indistinguishable counterparts which, while sharing a number of important local properties, either do not include a singularity to the past of every point or else do not have the sort of time ordering intuitively required for a cosmic beginning. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) (Quantum) reference frames, relational observables, gauge reduction and physical interpretation https://arxiv.org/abs/2603.04072 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04072v1 Announce Type: cross Abstract: It is mandatory to know how to operationally define and translate a reference frame into mathematics, in order that a physical interpretation of theory calculations in terms of observational data is possible. The situation is particularly challenging for gauge systems such as General Relativity where spacetime coordinates are subject to spacetime diffeomorphisms considered as gauge transformations turning coordinates into non-observables. This motivates the idea of operationally defined (material) reference frames which specify coordinates in terms of matter or geometry reference fields leading to the concept of relational observables, relational reference frames and gauge reduction. Upon quantisation, all fields become operator valued distributions. Now new conceptual and technical questions arise such as: Should one reduce before or after quantisation and how are the reference fields quantised respectively in either route? Is a reference frame itself subject to quantisation and how are different quantum reference frames related? How does the gauge reduction fit into this, i.e. how can it be that a certain reference field is considered a non-observable in one reference frame and an observable in another which upon quantisation even displays fluctuations? How precisely are gauge dependent fields interpreted in terms of the relational observables in a given reference frame? What is the relative dynamics, e.g. how exactly are physical Hamiltonians of two relational reference frames related? The present conceptual work addresses these and related questions in a non-perturbative field theory context of sufficient generality to cover General Relativity coupled to standard matter. A central role is played by the concept of the relational reference frame transformation (RRFT) for which a general formula is derived and its properties are explored. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Chern-Simons corner phase space in 4D gravity from BF-BB theory https://arxiv.org/abs/2603.03429 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03429v1 Announce Type: cross Abstract: We investigate an approach to determine the correct Poisson brackets of fields restricted to codimension 2 and 3 surfaces in 4D gravity, which are of great potential use in holographic setups and discretisation. Employing a specific BF-BB type parametrisation of gravity which relaxes Plebanski's simplicity constraints, we find that gravity in 4 dimensions carries Chern-Simons like phase spaces in codimension 2 and Kac-Moody algebras in codimension 3. The necessary gauge algebra in this context shows that the appropriate generalisation of the double $\mathcal{D}\mathfrak{so}(1,2)$ of 3D gravity is the Maxwell algebra, $\mathfrak{g}=\mathfrak{so}(1,3)\ltimes(\mathbb{R}^{1,3}\tilde\oplus \mathfrak{so}(1,3)^\ast)$. This realises the corner Poisson bracket of the spin connection for the first time and shows it is off-shell commutative, while the corner metric is noncommutative. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Universality classes, Thermodynamics of Group Entropies, and Black Holes https://arxiv.org/abs/2603.02385 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.02385v1 Announce Type: cross Abstract: Conventional Boltzmann--Gibbs statistical mechanics successfully describes systems with weak to moderate correlations, where the number of accessible configurations $W(N)$ grows exponentially with the number of degrees of freedom~$N$. However, this framework breaks down for systems with strong correlations or long-range interactions, for which the configuration space exhibits non-exponential growth. While numerous generalized entropies have been proposed to address this limitation, a coherent link to classical thermodynamic laws has remained elusive. Here, we propose group entropies as a unifying framework, defining universality classes of entropies through the asymptotic scaling of $W(N)$, each yielding an extensive entropy. We show that this approach provides the basis for a consistent thermodynamic formulation beyond the Boltzmann--Gibbs paradigm. In particular, by expressing these entropies in terms of thermodynamic state variables and taking the thermodynamic limit, we demonstrate their consistency with classical thermodynamics, in close analogy to the emergence of the Clausius entropy from the Boltzmann--Gibbs formalism. Focusing on the zeroth thermodynamic law, we identify the empirical temperature and, by using Carath\'{e}odory's formulation of the second law, we derive the associated absolute temperature. As an application of the thermodynamic framework obtained, we analyze black-hole thermodynamics using the group entropy class corresponding to stretched-exponential behavior of $W(N)$. In particular, we show that a hallmark property of black holes -- their negative specific heat -- emerges naturally within this framework while the entropy remains extensive. This result holds for the stretched-exponential entropies associated with both the Bekenstein--Hawking and Barrow entropy scalings. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Gravitational confinement of ghost scalar fields in neutron stars https://arxiv.org/abs/2603.04400 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04400v1 Announce Type: new Abstract: We investigate the effects, stability, and nonlinear dynamics of ghost scalar matter modeled as a field with a negative kinetic term confined within the cores of neutron stars. To this end, we analyze static configurations of the coupled Einstein-Euler-(ghost, complex) Klein-Gordon system and then we perform fully dynamical numerical evolutions of illustrative cases. Our results demonstrate that neutron stars can gravitationally confine a finite amount of ghost matter and support continuous families of equilibrium solutions, indicating that these configurations are not the result of fine tuning. We analyze the properties of the final states and find that the neutron star undergoes a persistent pulse-like oscillatory motion. In particular, we explicitly compute the frequency synchronization between the stellar fluid oscillation modes and those of the ghost scalar sector. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Non-Hermitian Quantum Mechanics with Applications to Gravity https://arxiv.org/abs/2603.04375 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04375v1 Announce Type: new Abstract: Hermiticity is usually treated as a foundational axiom of quantum mechanics, guaranteeing real spectra and unitary time evolution. In this work we argue that Hermiticity is more naturally understood as a symmetry law arising from the global conservation of an inner product current. We show that in spacetimes admitting complete Cauchy surfaces without boundary flux this conservation reduces to the familiar Hermiticity condition of the canonical inner product. However, in the presence of causal horizons, most strikingly in black hole geometries, this conservation law becomes obstructed for restricted observers. Tracing over inaccessible degrees of freedom then inevitably yields completely positive trace preserving dynamics with an effective non-Hermitian generator. Using quantum thermodynamics and the monotonicity of relative entropy, we demonstrate that the generalized second law may be reinterpreted as an entropy balance that compensates precisely for the flux of inner product charge through the horizon. The structure of Einstein equations, through the Bianchi identity and the Raychaudhuri focusing equation, provides the geometric mechanism underlying this balance. We also show that black hole ringdown can serve as a realistic observational probe of this idea and may provide quantitative upper bounds on the strength of horizon-induced inner product flux. In this way gravity, entropy production, and effective non-Hermiticity are unified under a single structural principle, with Hermiticity emerging as the special case of globally conserved inner product symmetry. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Non-minimally coupled loop quantum inflation with inverse-volume corrections https://arxiv.org/abs/2603.04182 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04182v1 Announce Type: new Abstract: We study slow-roll inflation driven by a scalar field non-minimally coupled to gravity within the effective framework of Loop Quantum Cosmology (LQC), including inverse-volume corrections. We consider two physically motivated classes of potentials, a Higgs-like quartic potential $V\propto\phi^{4}$ and string-inspired fractional monomial potentials $V\propto\phi^{p}$ with $p<1$. Working at first order in the slow-roll expansion, we derive analytic expressions for the inflationary observables, namely the scalar spectral index $n_s$, the tensor-to-scalar ratio $r$, and the running $\alpha_s\equiv dn_s/d\ln k$, and then solve the corrected background dynamics numerically to obtain quantitative predictions. Confronting these results with current observational constraints from Planck 2018 and ACT DR6, we find that the model can lie within the allowed region of the $(n_s,r,\alpha_s)$ parameter space, including a mild preference for slightly larger $n_s$, as suggested by recent ground-based measurements. We also compute the probability of achieving sufficient slow-roll inflation in this setting. Although effective LQC replaces the initial singularity with a nonsingular quantum bounce, the likelihood of a sufficiently long inflationary phase depends on the pre-inflationary dynamics and on the inflaton potential. Using the canonical Liouville measure on the effective phase space, we determine the fraction of post-bounce trajectories that yield sufficient inflation and find that the non-minimal coupling parameter $\xi$ substantially enlarges the phase-space volume of favorable initial conditions relative to the minimally coupled case, exhibiting an attractor-like enhancement that saturates at large $\xi$. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Stationary axisymmetric systems that allow for a separability structure https://arxiv.org/abs/2603.04047 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.04047v1 Announce Type: new Abstract: We develop a systematic framework for formulating and solving the conditions that lead to separability in stationary, axisymmetric spacetimes in the presence of matter fields. Guided by Carter's metric form, we introduce a general stationary, axisymmetric metric ansatz that allows for a transparent separation of radial and angular variables. This construction yields a broad family of stationary rotating solutions admitting separability structures. To illustrate the applicability of the formalism, we explicitly construct several examples, including a rotating black hole with a global monopole supported by anisotropic matter, as well as a new class of rotating wormhole geometries. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) The COSMIC WISPers White Paper: The physics case for Weakly Interacting Slim Particles https://arxiv.org/abs/2603.03433 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03433v1 Announce Type: cross Abstract: Axions and other very weakly interacting slim particles (WISPs), with masses below 1 GeV, arise naturally in many extensions of the Standard Model of particle physics. In particular, they could offer a new framework to explain the nature of dark matter and may help address a range of puzzling observations in astrophysics and particle physics. This review provides an overview of ongoing WISP searches and outlines the prospects for the next decade, spanning their theoretical motivation, indirect signatures in astrophysical observations, and dedicated laboratory experiments. It is based on the work carried on by the EU-funded COST Action ``Cosmic WISPers in the Dark Universe: Theory, astrophysics, and experiments'' (CA21106, https://www.cost.eu/actions/CA21106). This network plays a key role in coordinating and supporting WISP searches across Europe, while also contributing to the development of a roadmap aimed at securing European leadership in this research area. It is emphasized that Europe is currently pursuing a rich, diverse, and cost-effective experimental program, with the potential to deliver one or more transformative discoveries. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Scalar quasinormal modes of rotating black holes in parity-violating gravity https://arxiv.org/abs/2603.03722 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03722v1 Announce Type: new Abstract: Recently, an exact rotating black hole solution in a parity-violating theory of gravity was obtained via a conformal transformation of the Kerr solution in general relativity, with parity-violating effects encoded in the conformal factor. We study the quasinormal modes (QNMs) of a test scalar field minimally coupled to gravity on this conformal Kerr background, treating the parity-violating effects perturbatively while allowing for arbitrary black hole spin, from the non-rotating case to the near-extremal regime. For low spin, we derive a perturbative formula for the QNM frequencies that includes the leading-order parity-violating correction. For high spin, particularly in the near-extremal regime, we find sizable deviations from the Kerr QNM frequencies. Our results point to a new avenue for probing parity-violating physics in the strong-gravity regime through black hole QNMs. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) The effects of non Bunch-Davies initial conditions on gravitationally produced relics https://arxiv.org/abs/2603.03430 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03430v1 Announce Type: new Abstract: Typical gravitational production of relics from amplification of inflationary perturbations assumes Bunch-Davies initial conditions, i.e. a vacuum with initially no particles. In this paper we investigate the impact of non Bunch-Davies initial conditions to the final abundance of relics, with particular attention to the parameter space where the total dark matter abundance is reproduced. We present a general framework for any initial condition, through which we show their non-trivial effect on both spectrum and late-time abundance. We argue that for particles whose source of conformal symmetry breaking comes only from a mass term (spin-1/2 fermions and conformally coupled scalars), the choice of initial conditions has little impact on the mass range relevant to dark matter. For other particles, e.g. the longitudinal mode of spin-1, we see a large deviation from the standard computation. We exemplify and quantify our results with an initial thermal state and a two-stage inflation scenario, highlighting that the total dark matter can be obtained for a wide range of masses. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Lower bound on the radii of black-hole shadows https://arxiv.org/abs/2603.03421 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03421v1 Announce Type: new Abstract: The non-linearly coupled Einstein-matter field equations predict the existence of shadows with well-defined boundaries around black holes. We prove that, in spherically symmetric hairy black-hole spacetimes whose matter fields satisfy the weak energy condition, the radii of these shadows are bounded from below by the dimensionless relation $r_{\text{sh}}/r_{\text{H}}\geq 3\sqrt{3}/2$, where $r_{\text{H}}$ is the horizon radius of the central hairy black hole. The characteristic shadow of the (bald) Schwarzschild black-hole spacetime saturates the analytically derived lower bound. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) New symmetry for the imperfect fluid https://arxiv.org/abs/2603.03397 Thu, 05 Mar 2026 00:00:00 -0500 arXiv:2603.03397v1 Announce Type: new Abstract: We will address the existence of a new symmetry for an imperfect fluid by introducing local four-velocity gauge-like transformations for the case when there is vorticity. A similar tetrad formulation as to the Einstein-Maxwell spacetimes formalism presented in previous manuscripts will be developed in this manuscript for the imperfect fluids. The four-velocity curl and the metric tensor will be invariant under these kind of four-velocity gauge-like local transformations. While the Einstein-Maxwell stress-energy tensor is locally gauge invariant under electromagnetic gauge transformations, the perfect fluid stress-energy tensor will not be invariant under four-velocity gauge-like local transformations. We will dedicate our analysis to the imperfect fluid stress-energy tensor that will be invariant under local four-velocity gauge-like transformations when additional transformations are introduced for several variables included in the stress-energy tensor itself. We will also pay special attention to the construction of a vorticity stress-energy tensor invariant under local four-velocity gauge-like transformations. An application on neutron stars will be developed in order to show the simplifications brought about by these new tetrads. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Zero-point length as a topological protection of black hole regularity https://arxiv.org/abs/2603.02295 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02295v1 Announce Type: new Abstract: We investigate the thermodynamic topology of regular black holes with zero-point length using an extended first law that includes the zero-point length stored in the geometry. By treating the regularization scale $l_0$ as a thermodynamic variable, we analyze the Hessian geometry of the thermodynamic manifold and demonstrate that the vector field $\vec{\phi} = (T, \Psi)$, where $T$ is the temperature and $\Psi$ is the conjugate to $l_0$, never vanishes in the physical parameter space for $l_0 > 0$. This implies the absence of Morse critical points and a vanishing winding number ($W = 0$), indicating topological protection against the formation of naked singularities. Crucially, we show that in the singular limit $l_0 \to 0$, a non-zero winding number ($W = 1$) emerges, characterizing the Schwarzschild singularity as a topological defect. The conservation of this topological invariant under smooth evolution provides a rigorous topological formulation of the weak cosmic censorship conjecture: the presence of zero-point length not only regularizes the spacetime background but also enforces topological protection against the formation of singularities, preventing black hole-to-naked singularity transitions. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Shadow and Thermodynamics of deformed Schwarzschild-AdS black hole with a Cloud of Strings embedded in Perfect Fluid Dark Matter https://arxiv.org/abs/2603.02352 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02352v1 Announce Type: new Abstract: We investigate the optical and thermodynamic properties of a deformed Schwarzschild Anti-de Sitter (AdS) black hole coupled to a cloud of strings and embedded in perfect fluid dark matter. We analyze the photon sphere and the corresponding black hole shadow, determining how these observables are affected by the string cloud, dark matter distribution, and geometric deformation. The thermodynamic behavior is studied through both the quasi-homogeneous fundamental equation within the classical physical approach and the geometric framework of geometrothermodynamics (GTD), showing full consistency between the two descriptions. In the extended phase space, we examine the critical structure and phase behavior of the system. Our analysis reveals that neither the geometric deformation nor the dark matter parameter generates new phase transitions; criticality emerges only in the vicinity of the Reissner--Nordstr\"om--AdS solution (RN--AdS), where the deformation parameter effectively plays the role of an electric charge squared. These results clarify the interplay between matter distributions, geometric deformations, and the phase structure of AdS black holes. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Generalized Ernst Potentials for arbitrary Dilatonic Theories https://arxiv.org/abs/2603.02384 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02384v1 Announce Type: new Abstract: In this work, we generalize Ernst potentials to the Einstein-Maxwell-Dilaton case and explicitly write the corresponding potential space metric. Since this metric is five-dimensional in potential space, we generalize the corresponding Newman-Penrose coefficients for this metric and compare this formalism with previous approaches to show that this formulation is very convenient for analyzing these spacetimes and finding new exact solutions. We show how to obtain old exact solutions and some new ones with very interesting properties. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Orbital Dynamics and Gravitational Wave Signatures of Extreme Mass Ratio Inspirals in Galactic Dark Matter Halos https://arxiv.org/abs/2603.02414 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02414v1 Announce Type: new Abstract: In astrophysics, extreme mass ratio inspiral (EMRI) systems, which consist of a central supermassive black hole and a stellar-mass compact object (SCO), are typically embedded in galactic dark matter (DM) halos. This dark matter environment inevitably affects the orbital dynamics of the SCO and the gravitational wave (GW) signals emitted by the system. In this work, we select two typical dark matter halo profiles -- the Navarro-Frenk-White (NFW) and Beta models -- to systematically investigate their specific impacts on the long-term orbital evolution of the SCO. By incorporating three dissipative mechanisms -- dynamical friction, accretion, and gravitational radiation reaction -- our results demonstrate that, compared to a pure vacuum medium, the presence of a dark matter halo significantly alters the trajectories of precessing orbits, the dynamical evolution of orbital parameters, and the waveforms and phases of the emitted gravitational waves. Due to the strong accretion effect within the NFW model, the energy flux exhibits a distinctive "cusp" feature, marking a reversal from net energy loss to gain at a specific semi-latus rectum, which is a phenomenon absent in the Beta model. Although short-term observations may not be sufficient to distinguish between the NFW and Beta models, their differences become evident over long-term orbital evolution. The gravitational waveforms computed using the NFW and Beta models exhibit a phase shift, which could be detectable in high-density DM environments. This phase shift becomes even more pronounced for higher eccentric orbits and longer observation times. These results offer a theoretical framework for probing environmental effects on EMRIs across different dark matter models using future space-based gravitational wave observatories. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) A note on splitting solutions in $4+1$ dimensional quadratic gravity https://arxiv.org/abs/2603.02981 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02981v1 Announce Type: new Abstract: In the present paper we consider anisotropic cosmological vacuum solutions in (4+1) dimensional general quadratic gravity. In particular, we present a solution with 3 equal and 1 different Hubble parameters, and study its stability. We show that for a certain range of coupling constants this solution is stable. This means that initially totally anisotropic 4-dim Universe can evolve naturally to a product of 3-dim isotropic subspace and 1-dim space. By numerical integration of equations of motion we construct bassin of attraction of this solution which covers part of the initial conditions space with non-zero measure. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Carrollian correlators in black hole perturbation theory https://arxiv.org/abs/2603.03033 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.03033v1 Announce Type: new Abstract: In this note, we clarify the relationship between the two-point Carrollian correlator and massless scattering in black hole background. It turns out that there are two kinds of Carrollian correlators at the null boundaries of each asymptotically flat spacetime. The correlator from $\mathscr I^-$ to $\mathscr I^+$ should be regularized by subtracting the flat space analog, and it is the position space version of the reflection amplitude of massless scattering. On the other hand, the correlator from $\mathscr I^-$ to the future horizon $\mathcal H^+$ is absent in flat space, and it is the position space version of the transmission amplitude. The poles of the Carrollian correlators are governed by the null geodesics from $\mathscr I^-$ to $\mathscr I^+$ or $\mathcal H^+$, and they define two kinds of classical equations in Carrollian space. These equations establish the relationship between the Shapiro time delay and the deflection angle for light rays and should be understood as the dual descriptions of the quasinormal modes (QNMs) and the branch cut of the Green's function. We find that the time delay contains a logarithmic/quadratic behavior for the correlator from $\mathscr I^-$ to $\mathscr I^+/\mathcal H^+$ for small deflection angles. On the other hand, the time delay is always increasing linearly for both correlators when the deflection angle is large. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Emergent $\Lambda$CDM cosmology from a fractional extension of Newtonian gravity https://arxiv.org/abs/2603.03113 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.03113v1 Announce Type: new Abstract: We propose a minimal single-parameter extension of Newtonian gravity obtained by introducing a time-dependent fractional kernel characterized by a deformation parameter $\alpha$. This modification induces an effective fractional sector in the dynamics. Despite the appearance of a friction-like term in the equations of motion, we demonstrate the existence of a conserved quantity that contains a memory-like fractional kinetic contribution. By consistently generalizing the standard potential to an effective potential that depends on $\alpha$, the resulting cosmological equations exhibit background dynamics that are dynamically equivalent to relativistic cosmology. Remarkably, with a single unified potential and without introducing a cosmological constant by hand, the radiation-dominated era, the matter-dominated era, and the present accelerated phase are simultaneously and self-consistently reproduced. The structural presence of $\alpha$ in all physical observables allows theoretical and observational constraints to be imposed, indicating that compatibility with the data requires $|\alpha - 1| \ll 1$. In the limit $\alpha \to 1$, the theory smoothly reduces to standard Newtonian gravity. These results show that an emergent $\Lambda$CDM-like cosmological dynamics can arise from a single-parameter fractional deformation of Newtonian gravity. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Quasinormal modes of four-dimensional regular black holes in quasi-topological gravity: Overtones' outburst via WKB method https://arxiv.org/abs/2603.03189 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.03189v1 Announce Type: new Abstract: We study quasinormal modes of scalar, electromagnetic, and Dirac perturbations of four-dimensional regular black holes arising in non-polynomial quasi-topological gravity. Starting from a more general class of metric functions constructed within the same framework, from which two representative cases are selected for detailed analysis, we examine their spectral properties. While the fundamental mode changes smoothly with the regularization parameter, higher overtones display a markedly enhanced sensitivity to near-horizon modifications, leading to the characteristic outburst of overtones. Remarkably, pushing the WKB approximation to sufficiently high orders with Pade resummation already allows one to detect the onset of this effect. Time-domain analysis and the Leaver method confirm that the relative error of the higher-order WKB approach is much smaller than the observed effect. Our results indicate that overtone dynamics provides a sensitive probe of geometrically regular black holes and that high-order WKB methods remain capable of capturing nontrivial spectral features beyond the fundamental mode. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) A Quantum Weyl Conjecture https://arxiv.org/abs/2603.02311 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02311v1 Announce Type: cross Abstract: We perform a quantum probing of colliding plane-wave space-times. In particular, we consider the Khan-Penrose and the Ferrari-Ib\'a\~nez solutions, which admit a strong and a weak singularity after the two waves collide. While we find that, like Schwarzschild, for the Khan-Penrose solution the singularity cannot be probed by quantum field theory, the Ferrari-Ib\'a\~nez singularity can be traversed. Our results culminate in a quantum Weyl conjecture: The significant geometric property to classify space-times with respect to quantum probes is given by the Coulomb part of the Weyl tensor. We then use this conjecture to sketch a possible backreaction scenario for plane waves. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) One-loop aspects of de Sitter axion wormholes https://arxiv.org/abs/2603.02335 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02335v1 Announce Type: cross Abstract: We discuss aspects of the Euclidean path integral around axion-supported de Sitter wormholes, at one-loop order. We numerically compute the phase of the path integral around these solutions, as well as for a certain "multiple wormholes" generalization, and interpret this phase in different regimes. When the geometry is well approximated by a sphere with a small handle, the wormhole admits an effective description as a sphere with two local operator insertions, whose positions fluctuate around the antipodal configuration. The antipodal configuration is an extremum of the position integral for the operators, but we show that it is an unstable one. Accordingly, the phase of the wormhole solution can be viewed as the Polchinski phase in the sphere, multiplied by an additional phase from the integral over positions of the effective local operators. Using our expressions for the one-loop determinant, we also estimate the EFT coefficients of the dual bilocal operators in odd spacetime dimensions, to one-loop order. Lastly, we also discuss "maximal flux" solutions, which have $S^{1}\times S^{D-1}$ geometry. Their Lorentzian continuations are Einstein static universes, so we call them "Einstein wormholes". In this limit, we determine the spectrum of fluctuations analytically and show that the phase of the path integral around this solution is entirely accounted for by the well-known instability of the Einstein static universe. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) The Routh of the Attractor Mechanism https://arxiv.org/abs/2603.02559 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02559v1 Announce Type: cross Abstract: We investigate and clarify various aspects of the effective dynamics of Maxwell-Einstein-scalar theories in the background of static, spherically symmetric and asymptotically flat extremal black holes in four space-time dimensions. This rigorously places the one-dimensional effective radial dynamics governed by the Attractor Mechanism, through the critical points of the Ferrara-Gibbons-Kallosh effective black hole potential $V_{BH}$, into the Routhian formalism, a framework which is intermediate between the Lagrange and Hamilton ones, based on a partial Legendre transform, and especially relevant in presence of cyclic variables. We elucidate and analyze the interplay of a trio of effective functionals: the aforementioned $V_{BH}$, Sen's entropy functional $\mathcal{E}$, and the relevant effective Routhian functional $\mathcal{R}$. Through their critical values at the event horizon, such functionals determine the Bekenstein-Hawking and the Wald entropy of the extremal black hole. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Lorentz violating quadratic gravity https://arxiv.org/abs/2603.02980 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02980v1 Announce Type: cross Abstract: In this paper we explore the perturbative renormalization and study the classical dynamics of the bumblebee model coupled to quadratic gravity, a theoretical setting that allows the violation of Lorentz symmetry. Such a violation arises from a vector field whose potential is engineered to induce a nonzero vacuum expectation value (VEV), thereby leading to the emergence of a preferred direction in spacetime and, consequently, to the spontaneous breaking of Lorentz symmetry. Working in dimensional regularization and expanding the metric around flat space, we compute the one-loop divergent parts of the two-point functions of the bumblebee and graviton fields, with special emphasis on the role of Lorentz-violating insertions in internal lines. These results determine the counterterms required to renormalize the gravitational and bumblebee sectors in the presence of a preferred background direction, and make explicit how Lorentz-violating interactions feed back into the UV structure of quadratic gravity. On the classical side, we derive the field equations and identify exact solutions supported by bumblebee backgrounds. In particular, we show that the Schwarzschild geometry remains an exact solution for an appropriate bumblebee configuration, even in the presence of non-minimal couplings. We close with a discussion of the operator content suggested by the one-loop structure and of prospective extensions to cosmological and less symmetric backgrounds. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Euclidean Thermodynamics and Lyapunov Exponents of Einstein-Power-Yang-Mills AdS Black Holes https://arxiv.org/abs/2504.12890 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2504.12890v2 Announce Type: replace Abstract: We study the thermodynamics of Einstein-Power-Yang-Mills AdS black holes via the Euclidean path integral method, incorporating appropriate boundary and counterterms. By analyzing unstable timelike and null circular geodesics, we demonstrate that their Lyapunov exponents reflect the thermodynamic phase structure obtained from the Euclidean action. Specifically, the small-large black hole phase transition, analogous to a van der Waals fluid, is signaled by a discontinuity in the Lyapunov exponent. Treating this discontinuity as an order parameter, we observe a universal critical exponent of $1/2$, consistent with mean-field theory. These results extend previous insights from black hole spacetimes with Abelian charges to scenarios involving nonlinear, non-Abelian gauge fields, highlighting the interplay between black hole thermodynamics and chaotic dynamics. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) A pedagogical approach to the black hole information issue https://arxiv.org/abs/2505.17164 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2505.17164v4 Announce Type: replace Abstract: We provide a pedagogical introduction to the concepts underlying black hole information loss, intended for readers familiar with special relativity and quantum mechanics. We emphasize that there is no paradox of information loss, and that proposals suggesting deviations from well-established theories at arbitrary regimes are inherently contradictory. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Cosmology of Cubic Poincar\'e Gauge gravity https://arxiv.org/abs/2506.17017 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2506.17017v2 Announce Type: replace Abstract: In this paper, we study flat FLRW cosmology for a Poincar\'e gauge theory containing cubic invariants that is free from ghosts in arbitrary backgrounds in the axial and vector sectors of the torsion tensor. The new degrees of freedom can be related to hypermomentum but continue to be dynamical even in vacuum. These extra degrees of freedom open a more natural way in which to construct potential gravitational models that provide possible ways to modify astrophysical and cosmological physics. In this framework, we study two particular branches of the theory where preliminary routes of exploring these new variables are exposed. The first is the branch where the hypermomentum vanishes, while the second branch involves the setting where the perfect fluid and hypermomentum parts of the sources are independently conserved. In both settings, we find generically faster expanding cosmologies with similar estimates of the cosmic matter content as in the standard model of cosmology. Cubic Poincar\'e Gauge gravity offers an interesting theoretical basis on which to study cosmology, and indicates some preliminary positive constraints when compared with observational constraints. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Dancing in the dark: probing Dark Matter through the dynamics of eccentric binary pulsars https://arxiv.org/abs/2507.16904 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2507.16904v2 Announce Type: replace Abstract: We investigate the dynamics of eccentric binary pulsars embedded in dark matter environments. While previous studies have primarily focused on circular orbits in collisionless dark matter halos, we extend this framework to eccentric systems and explore their interaction with ultralight scalar fields. Adopting a perturbative approach, we compute the modifications to the orbital period induced by dark matter-driven dynamical friction. Our results show that orbital eccentricity amplifies the imprints of non-vacuum environments on binary dynamics, underscoring the potential of such systems as sensitive probes for dark matter signatures. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) QNM families: classification and competition https://arxiv.org/abs/2510.02033 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2510.02033v2 Announce Type: replace Abstract: The perturbation spectra of black holes beyond standard vacuum black hole solutions within generalrelativity (GR) may exhibit complex structures with long-lived modes. This usually generates echolikemodulations on the ringdown signal, which typically originate from modified boundary conditionsassociated with exotic compact objects. Recent studies also reveal that they can instead arise from themultipeaked structure of the perturbation potential. However, while some case-by-case studies have beencarried out, a framework for understanding the internal structure of such spectra, the physical nature ofdifferent mode families, and their dynamical excitation remains to be fully systematized. In this paper,we address this issue by proposing a potential methodology that combines frequency-domainclassification with time-domain analysis, using a hairy Schwarzschild black hole that admits adouble-peak perturbative potential as a theoretical platform. Our analysis of the quasinormal modespectrum identifies two distinct families of modes: the photon sphere (PS) family, arising fromdelocalized scattering resonances, and the echo family, corresponding to highly localized quasiboundstates. We then develop a windowed energy analysis framework in the time domain, which discloses adynamic competition for dominance between these families. In particular, our results explicitly showthat this competition is sensitive to the properties of the initial perturbation source, and that higher-overtone echo modes can dominate in the observed signal, which are in contrast to the standard PS modein GR. This study establishes the dynamic evolution of this energy competition as a new observationalsignature for probing new physics and further motivates a supplemental framework for analyzing long-lived ringdown signals. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Quasi-normal modes of the Ay\'on-Beato-Garc\'ia black hole surrounded by quintessence https://arxiv.org/abs/2510.18846 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2510.18846v2 Announce Type: replace Abstract: We compute the quasi-normal modes of scalar, electromagnetic, and gravitational perturbations of an Ay\'on-Beato-Garc\'ia black hole surrounded by quintessence using the Asymptotic Iteration Method (30 iterations). The results are compared with the WKB approximation to evaluate the robustness and accuracy of AIM. The results show that the real part of the frequencies increases with the charge parameter, while the absolute value of the imaginary part decreases as the charge parameter increases. In contrast, both the real part and the absolute value of the imaginary part decrease as the quintessence parameter $c$ increases. These trends are observed for both values of the quintessence state parameter, $\omega_q=-2/3$ and $\omega_q=-4/9$; however, the effects become more pronounced as $\omega_q$ approaches $-1$ corresponding to cosmological constant. The quasi-normal frequencies tend to have finite values, which could facilitate their observational detection. Moreover, the presence of quintessence leads to a slower damping of the perturbations. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Breaking Eternal Inflation: Empirical Viability of a Spontaneous Collapse Scenario https://arxiv.org/abs/2510.26378 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2510.26378v2 Announce Type: replace Abstract: We revisit an inflationary scenario in which primordial inhomogeneities arise from a quantum collapse, a stochastic mechanism described in the context of quantum collapse theories in its continuous version and within semiclassical gravity. The predictions of the model show a non-conventional scalar spectrum governed by two new parameters in the collapse rate, whose aim is twofold: on one side, to account for the primordial cosmic structure, and on the other to explain the suppression amplitude associated with long-wavelength modes, thereby eliminating the occurrence of eternal inflation. Furthermore, this model can contribute to accounting for the lack of power anomaly in the low $l$ angular power spectra of the Cosmic Microwave Background (CMB). Using the latest data from the Planck (2018) collaboration, we establish observational constraints on the model parameters, which produce a characteristic low-$\ell$ suppression in the cosmic microwave background spectrum. We conclude that the Planck data support the solution presented in the previous works, in other words, that the model allows us to solve simultaneously the emergence of the cosmic structure and, at the same time, avoid the eternal inflation scenario. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Stochastic Limit of Growing Gravitational Wave Memory from Sources in the Early Universe and Astrophysical Sources https://arxiv.org/abs/2511.06548 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2511.06548v3 Announce Type: replace Abstract: We show that the stochastic background of gravitational wave memory of growing type leads to a fractional Brownian motion increasing at the order of $t^{H}$ for large $t$ where $\frac{1}{2} < H <1$. This beats the scaling law of Brownian motion. In this article we investigate sources of gravitational waves in the early universe as well as in astrophysical settings. Cosmological sources may include primordial black holes or other sources immediately after the Big Bang when there were pockets of hot material, and large density fluctuations. Gravitational waves from mergers of primordial black holes produce memory. We show that due to the conditions in which these are taking place the gravitational wave memory will be increasing in time following a certain power law. Corresponding results hold for any gravitational wave memory from a cosmological source where the surrounding conditions are similar. The stochastic limit of these memories is a stochastic process growing in time faster than the $\sqrt{t}$ scaling law of Brownian motion. The latter is also typical for noise and for the limit of memory events as they have been mostly considered in the literature. In an expanding universe, the memory is enhanced by the expansion itself. Our results provide a tool to extract gravitational wave sources of this type from data using this memory signature. This would be particularly useful for the PTA data that has been already observed, answering the long-standing question on how to extract memory signals from the data. Further, the new results open up a new door to explore the conditions right after the Big Bang using the long-range dependence and further probability analysis. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Two-stage Convolutional Neural Network for six-dimensional phase space reconstruction https://arxiv.org/abs/2603.02733 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02733v1 Announce Type: new Abstract: In particle accelerators, full knowledge of the six-dimensional (6D) beam phase space is crucial but difficult to obtain with conventional beam diagnostics. We develop a two-stage convolutional neural network (CNN) that reconstructs the 6D phase space from only sixteen transverse $x-y$ screen images taken at a place with dispersion by different phase space rotation angles. The model is trained with simulation data of KEK-Accelerator Test Facility (ATF) injector with ASTRA. The real-space images in the chicane orbit at the KEK-ATF injector were acquired by varying the RF phase of the RF electron gun and the solenoid magnetic field. From these data, we reconstructed the 6D phase space distribution at the cathode surface and visualized it as 15 two-dimensional images covering all pairwise coordinate combinations. The time width and spatial spread of the electron beam at the cathode showed values consistent with the measured values at KEK-ATF. Compared to existing 6D beam imaging measurement techniques such as tomography, it significantly reduces measurement time and required computational resources, enabling the provision of a more practical 6D phase space measurement method. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Complementarity between atmospheric and super-beam neutrinos at ESSnuSB https://arxiv.org/abs/2603.02836 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02836v1 Announce Type: new Abstract: The ESSnuSB experiment aims to measure the leptonic CP phase $\delta_{CP}$ with an unprecedented resolution by probing neutrino oscillations at the second oscillation maximum. In the present work, the complementarity between the long-baseline neutrino program and atmospheric neutrinos is investigated for ESSnuSB. By simulating atmospheric neutrino events equivalent of 5.4 Mt$\cdot$year exposure, the resolution for $\delta_{\rm CP}^{}$ is found to improve from $7.5^\circ$ ($6.7^\circ$) to $7.1^\circ$ ($6.5^\circ$) at $1\sigma$~CL for $\delta_{\rm CP}^{} = -90^\circ$ ($+90^\circ$) with respect to super-beam neutrinos, resolving also the degeneracies arising from neutrino mass ordering. These findings highlight the synergies that exist between super-beam neutrinos and atmospheric neutrinos in ESSnuSB. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Search for a massless particle beyond the Standard Model in the $\Xi^0\to\Lambda + \text{invisible}$ decay https://arxiv.org/abs/2603.03199 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.03199v1 Announce Type: new Abstract: A search for a massless beyond-standard-model particle is performed in the decay $\Xi^{0}\to\Lambda+\text{invisible}$ using $(1.0087 \pm 0.0044)\times 10^{10}$ $J/\psi$ events collected with the BESIII detector at the BEPCII collider. No significant signal is observed and the upper limit on the branching fraction $\mathcal{B}(\Xi^{0}\to\Lambda+\text{invisible})$ is set to be $2.3 \times 10^{-4}$ at the $90\%$ confidence level. This is the first search for a flavor-changing neutral current process with missing energy in $\Xi^0$ decays. Throughout this paper, charge-conjugate processes are always implied. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Search for a narrow resonance with a mass between 10 and 70 GeV decaying to a pair of photons in proton-proton collisions at $\sqrt{s}$ = 13 TeV https://arxiv.org/abs/2603.03250 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.03250v1 Announce Type: new Abstract: The existence of a new spin-zero particle with a mass below the electroweak scale is predicted by several theoretical models. Searches for resonant production of photon pairs at the LHC are able to probe these models. We present a search for a narrow resonance produced through gluon fusion that decays into a pair of photons with an invariant mass between 10 and 70 GeV, using a proton-proton collision data set from the CMS experiment. This data set, corresponding to an integrated luminosity of 54.4 fb$^{-1}$, was recorded in 2018 at a center-of-mass energy of 13 TeV using a newly introduced diphoton trigger that enabled exploration of the low-mass diphoton spectrum. No significant excess above the expected background is observed. Upper limits are set on the product of the gluon fusion production cross section and the branching fraction of the diphoton decay of a narrow resonance. An interpretation of these limits within an effective field theory framework for axion-like particles is also provided. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) New high-sensitivity search for neutron to mirror-neutron oscillations at the PSI UCN source https://arxiv.org/abs/2602.23487 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2602.23487v1 Announce Type: cross Abstract: In a search for potential signals of neutron (n) to mirror-neutron (n') oscillations, a collaboration centered at the Paul Scherrer Institute (PSI) investigated the remaining parameter space claimed by anomalies with a dedicated high-sensitivity apparatus. An elaborate magnetic-field-mapping analysis and Monte Carlo simulation of the cumulative n-n' oscillation probabilities along the neutron trajectories inside the storage vessel complemented the neutron data analysis. Magnetic fields were scanned in the range 5 microT < B < 109 microT. No evidence of anomalous neutron losses was found. Consequently, new limits for the n-n' oscillation time constant were set. The parameter space, previously claimed for potential signals, has been excluded to 99.98 %. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) One-point energy correlator for deep inelastic scattering at small $x$ https://arxiv.org/abs/2603.02300 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02300v1 Announce Type: cross Abstract: We derive the expressions for the one-point energy correlator (OPEC) in deep inelastic scattering in the high-energy (small-$x$) limit within the Color Glass Condensate framework. The OPEC is computed as a function of the angle between the energy flow and the target proton or nucleus, enabling a systematic exploration of different momentum scales in the scattering process. Owing to the momentum sum rule, the dependence on fragmentation functions cancels, leaving the dipole amplitude as the only nonperturbative input. As a result, the OPEC provides a clean and direct probe of gluon saturation dynamics at small $x$. We present numerical results for representative kinematic configurations relevant to the future Electron--Ion Collider, demonstrating sizable nuclear suppression effects and highlighting the sensitivity of this observable to saturation phenomena. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Open system approach to neutrinos propagating in an ultralight scalar background https://arxiv.org/abs/2603.02382 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02382v1 Announce Type: cross Abstract: We examine decoherence in neutrino oscillations induced by an ultralight scalar field coupled to neutrinos. The scalar induces time- and position-dependent shifts in the neutrino mass matrix. Neutrinos sample different field configurations throughout an experimental data-taking period, which leads to damping effects in the oscillation pattern in the form of decoherence. By recasting the neutrino-scalar dynamics within the open quantum systems framework, we establish a mapping between a complete model and phenomenological decoherence approaches. We find that the parameter driving decoherence scales as $L^2/E^2$, where $L$ is the baseline and $E$ is the neutrino energy, as opposed to $L/E$ typically assumed in phenomenological studies of open system approaches to neutrino oscillations. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Internal Charge Amplification in Germanium at 77K and 4K: From Single-Free-Flight Bounds to a Physics-Informed Ionization Model https://arxiv.org/abs/2603.02391 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02391v1 Announce Type: cross Abstract: Internal charge amplification (ICA) in cryogenic high-purity germanium (HPGe) can lower detection thresholds by providing gain inside the detector crystal, but reliable operation requires a predictive estimate of the avalanche-onset \emph{critical electric field} \(E_{\mathrm{crit}}\). We present a compact framework for \(E_{\mathrm{crit}}\) at 77~K and 4~K (typical HPGe operating temperatures) that bridges (i) a mobility-based single-free-flight (SFF) upper bound with (ii) a physics-informed impact-ionization model incorporating energy-dependent scattering, nonparabolic (Kane) dispersion, intervalley transfer, and the high-energy ``lucky-drift'' tail. This unified treatment yields closed-form, design-useful relations, including \(E_{\mathrm{crit}}^{(\mathrm{PI})}=B(T)/\ln[A(T)d]\), and a practical calibration workflow that maps measured low-field mobility \(\mu(T)\) and gain curves \(M(V)\) (Chynoweth analysis) to device-level bias targets with propagated uncertainty bands. Example electron and hole estimates indicate that realistic transport typically lowers \(E_{\mathrm{crit}}\) relative to SFF and increases the predicted change in \(E_{\mathrm{crit}}\) between 77~K and 4~K. The resulting portable formulas connect materials/transport inputs to geometry, excess noise, and field shaping, providing design-ready guidance for stable, unipolar-favored ICA with controlled quenching in Ge and other cryogenic semiconductors. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Radiative decays of hadronic molecules: From confusion to inspiration https://arxiv.org/abs/2603.02671 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02671v1 Announce Type: cross Abstract: Radiative decays of hadronic states provide an essential source of information that can facilitate deciphering their nature and properties. However, a lot of confusion concerning radiative decays of hadronic molecules and their interpretation can be found in the literature. In this paper, we briefly review several types of such decays and pinpoint similarities and essential differences between them. In particular, we emphasise the crucial role played by the hierarchy of the scales relevant to the studied system and the resulting necessity of employing an approach that considers them appropriately. We illustrate the situation with several instructive examples. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Electroweak Higgs boson pair production: Updated inclusive cross sections https://arxiv.org/abs/2603.02764 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02764v1 Announce Type: cross Abstract: We present updated inclusive cross sections for electroweak Higgs boson pair production for energies of relevance to the LHC and High-Luminosity phase of the LHC. The cross sections are presented at N$^3$LO QCD+NLO EW for vector-boson fusion and NNLO QCD for associate production with a vector boson. We compute the cross sections using the most up-to-date theory inputs, both in the Standard Model and for a few anomalous values of the trilinear Higgs self-coupling. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Triply polarized $WWW$ at the LHC: first glimpse at LO https://arxiv.org/abs/2603.02917 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02917v1 Announce Type: cross Abstract: We present first results for triply polarized $WWW$ events at the LHC. The calculation is performed at leading order for fully leptonic decays using the Standard Model. Employing an inclusive kinematic cut setup, we found that the triply-transverse polarization fraction is about $51\%$, while the triply-longitudinal (LLL) fraction is smallest with $1.4\%$ for the $W^-W^+W^+$ process. The interference between different polarization amplitudes amounts to $+1.8\%$. Results for the $W^+W^-W^-$ case are similar. Based on known higher-order results for the diboson processes, radiative corrections are not expected to increase the LLL fraction to the level of tens of percent. This means that measuring the LLL cross section at the LHC will be very challenging. A new on-shell mapping for triboson processes, being a crucial element of polarized cross-section calculation, is also presented. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) From Reachability to Learnability: Geometric Design Principles for Quantum Neural Networks https://arxiv.org/abs/2603.03071 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.03071v1 Announce Type: cross Abstract: Classical deep networks are effective because depth enables adaptive geometric deformation of data representations. In quantum neural networks (QNNs), however, depth or state reachability alone does not guarantee this feature-learning capability. We study this question in the pure-state setting by viewing encoded data as an embedded manifold in $\mathbb{C}P^{2^n-1}$ and analysing infinitesimal unitary actions through Lie-algebra directions. We introduce Classical-to-Lie-algebra (CLA) maps and the criterion of almost Complete Local Selectivity (aCLS), which combines directional completeness with data-dependent local selectivity. Within this framework, we show that data-independent trainable unitaries are complete but non-selective, i.e. learnable rigid reorientations, whereas pure data encodings are selective but non-tunable, i.e. fixed deformations. Hence, geometric flexibility requires a non-trivial joint dependence on data and trainable weights. We further show that accessing high-dimensional deformations of many-qubit state manifolds requires parametrised entangling directions; fixed entanglers such as CNOT alone do not provide adaptive geometric control. Numerical examples validate that CLS-satisfying data re-uploading models outperform non-tunable schemes while requiring only a quarter of the gate operations. Thus, the resulting picture reframes QNN design from state reachability to controllable geometry of hidden quantum representations. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Improvement and assessment of the radiopurity of Micromegas readout planes https://arxiv.org/abs/2603.03274 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.03274v1 Announce Type: cross Abstract: Micromesh Gas Structures (Micromegas) as readout of gaseous Time Projection Chambers (TPCs) are being considered in experiments investigating rare phenomena, like the nuclear double beta decay, solar axion detection and low-mass dark matter interactions, due to their good performance on spatial and energy resolution and operation stability. In addition, as they are potentially made mainly of radiopure materials like copper and kapton, they are appropriate for ultra-low background conditions. After a promising first study of the radiopurity of Micromegas readout planes, here results after dedicated development at CERN obtained from new radioassays, performed at the Canfranc Underground Laboratory combining different techniques, are presented. Activity of the isotopes in the lower parts of the 238U and 232Th natural chains has been constrained by analyzing the BiPo sequences using the BiPo-3 detector to be <0.064 and <0.016 muBq/cm2 respectively, while a lowest 40K content of 0.102+-0.030 muBq/cm2 has been determined by gamma spectroscopy using a HPGe detector; the latter value implies a reduction of a factor 34 with respect to the 40K activity quantified in the first analyzed sample. These results confirm the suitability of the use of Micromegas as extremely radiopure readouts for rare event searches. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) New Limit on Axion-Like Dark Matter using Cold Neutrons https://arxiv.org/abs/2204.01454 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2204.01454v3 Announce Type: replace Abstract: We report on a search for dark matter axion-like particles (ALPs) using a Ramsey-type apparatus for cold neutrons. A hypothetical ALP-gluon-coupling would manifest in a neutron electric dipole moment signal oscillating in time. Twenty-four hours of data have been analyzed in a frequency range from 23 $\mu$Hz to 1 kHz, and no significant oscillating signal has been found. The usage of present dark-matter models allows to constrain the coupling of ALPs to gluons in the mass range from $10^{-19}$ to $4 \times 10^{-12}$ eV. The best limit of $C_G$/$f_a m_a = 2.7 \times 10^{13}$ GeV$^{-2}$ (95\% C.L.) is reached in the mass range from $2 \times 10^{-17}$ to $2 \times 10^{-14}$ eV. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Resonant Cancellation Effect in Ramsey-type Nuclear Magnetic Resonance Experiments https://arxiv.org/abs/2306.09663 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2306.09663v2 Announce Type: replace Abstract: We investigate the response of a Ramsey-type experiment on an additional oscillating magnetic field. This superimposed field is oriented in the same direction as the static main magnetic field and causes a modulation of the original Larmor spin precession frequency. The observable magnitude of this modulation reduces at higher frequencies of the oscillating field. It disappears completely if the interaction time of the particles matches the oscillation period, which we call resonant cancellation. We present an analytical approach that describes the effect and compare it to a measurement using a monochromatic cold neutron beam. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Search for nonresonant new physics signals in high-mass dilepton events produced in association with b-tagged jets in proton-proton collisions at $\sqrt{s}$ = 13 TeV https://arxiv.org/abs/2506.13565 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2506.13565v2 Announce Type: replace Abstract: A search for nonresonant new physics phenomena in high-mass dilepton events produced in association with b-tagged jets is performed using proton-proton collision data collected in 2016$-$2018 by the CMS experiment at the CERN LHC, at a center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 138 fb$^{-1}$. The analysis considers two effective field theory models with dimension-six operators; involving four-fermion contact interactions between two leptons ($\ell\ell$, electrons or muons) and b or s quarks (bb$\ell\ell$ and bs$\ell\ell$). Two lepton flavor combinations (ee and $\mu\mu$) are required and events are classified as having 0, 1, and $\geq$ 2 b-tagged jets in the final state. No significant excess is observed over the standard model backgrounds. Upper limits are set on the production cross section of the new physics signals. These translate into lower limits on the energy scale $\Lambda$ of 6.9 to 9.0 TeV in the bb$\ell\ell$ model, depending on model parameters, and on the ratio of energy scale and effective coupling, $\Lambda/g_*$, of 2.0 to 2.6 TeV in the bs$\ell\ell$ model. Lepton flavor universality is also tested by comparing the dielectron and dimuon mass spectra for different b-tagged jet multiplicities. No significant deviation from the standard model expectation of unity is observed. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Measurement of $C\!P$ asymmetry in $D^0 \to K^0_{\rm S} K^0_{\rm S}$ decays with Run 3 data https://arxiv.org/abs/2510.14732 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2510.14732v2 Announce Type: replace Abstract: A measurement of $C\!P$ asymmetry in $D^0 \to K^0_{\rm S} K^0_{\rm S}$ decays is reported, based on a data sample of proton-proton collisions collected with the LHCb detector in 2024 at a centre-of-mass energy of $13.6\,$TeV, corresponding to an integrated luminosity of $6.2\,\mathrm{fb}^{-1}$. The $D^0 \to K^0_{\rm S} \pi^+ \pi^-$ decay is used as calibration channel to cancel residual detection and production asymmetries. The time-integrated $C\!P$ asymmetry for the $D^0 \to K^0_{\rm S} K^0_{\rm S}$ mode is measured to be $$ {\cal A}^{C\!P} (D^0 \to K^0_{\rm S} K^0_{\rm S}) = (1.86 \pm 1.04\pm 0.41)\%, $$ where the first uncertainty is statistical, and the second is systematic. This measurement represents the most precise single-experiment determination of this quantity to date. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) A Nuclear Interferometer for Ultra-Light Dark Matter Detection https://arxiv.org/abs/2407.11112 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2407.11112v3 Announce Type: replace-cross Abstract: We propose the nuclear interferometer - a single-photon interferometry experiment based upon the thorium-229 nuclear clock transition - as a novel detector for ultra-light dark matter. Thanks to the enhanced sensitivity of this transition to the variation of fundamental constants, we find that possible realisations of such an experiment deploying either single ions or clouds of atoms have the potential to complement advanced very-long-baseline terrestrial clock atom interferometers in the search for ultra-light dark matter with scalar couplings to photons in the future. Nuclear interferometry may also offer an unparalleled window to new physics coupling to the QCD sector via quarks or gluons, with a discovery reach that could enhance existing and proposed experiments over a range of frequencies in the direction of well-motivated parameter space. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Prospects for observing the missing $2D$ and $1F$ charmonium states around 4 GeV https://arxiv.org/abs/2411.15689 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2411.15689v5 Announce Type: replace-cross Abstract: Our understanding of high-lying states within the charmonium family remains incomplete, particularly in light of recent observations of charmonium states at energies around 4 GeV. In this study, we investigate the spectroscopic properties of several high-lying charmonia, focusing on the $2D$ and $1F$ states. A mass spectrum analysis is conducted, incorporating the unquenched effects. We then present a detailed study of the strong decay properties, including partial decay widths for two-body strong decays permitted by the Okubo-Zweig-Iizuka (OZI) rule. Additionally, we explore the primary radiative decay channels associated with these states. Finally, we discuss the radiative transitions of the $2D$ and $1F$ states via $e^+e^-$ annihilation. Theoretical predictions provided here aim to guide future experimental searches for high-lying charmonium states at facilities such as BESIII, Belle II, LHCb, and the future STCF. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Development of a simulation and analysis framework for N{\nu}DEx experiment https://arxiv.org/abs/2508.13582 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2508.13582v4 Announce Type: replace-cross Abstract: N$\nu$DEx aims to search for the neutrinoless double beta decay in $^{82}$Se using a high pressure $^{82}$SeF$_6$ gas time projection chamber (TPC). This paper presents a simulation and analysis framework developed specifically for the N$\nu$DEx experiment. Using density functional theory and two-temperature theory, the reduced mobilities of SeF$_5^-$ and SeF$_6^-$ ions in SeF$_6$ were calculated, yielding values of 0.444 and 0.430 $\mathrm{cm^2V^{-1}s^{-1}}$ respectively, with an estimated uncertainty within 3\%. The TPC geometry, featuring a cathode, focusing plane, and anode structure, was modeled in COMSOL to compute electric fields. Signal and background events were generated using BxDecay0 and Geant4, while Garfield++ was employed to simulate charge transport and signal induction. Three-dimensional tracks were reconstructed from drift-time differences between the two assumed ion species using a breadth-first search algorithm. To demonstrate the framework's analytical capability, topological variables were taken from reconstructed tracks and used to define selection criteria. A boosted decision tree was then implemented to benchmark the signal-background separation. This simulation framework successfully validates the complete experimental workflow, serving as a robust tool for detector design and future sensitivity studies in the N$\nu$DEx experiment. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Emergent Gribov horizon from replica symmetry breaking in Yang--Mills theories https://arxiv.org/abs/2603.02838 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02838v1 Announce Type: new Abstract: We show that the Serreau--Tissier (ST) replica sector can dynamically generate a Gribov--Zwanziger (GZ)--type horizon functional in Yang--Mills (YM) theories. After integrating out the replica superfields, the expansion of the determinant of the Faddeev--Popov (FP) operator in the regulator $\zeta$ produces, at linear order in $\zeta$, a nonlocal kernel with the same color and Lorentz structure as the Gribov horizon functional, thereby defining an induced Gribov scale. Depending on the replica phase selected by the dynamics, the ST sector yields either (i) a local Curci--Ferrari (CF) screening mass (replica-symmetric phase) or (ii) an induced horizon-like interaction (replica-broken phase). In the latter case, the resulting BRST-invariant local formulation leads to a tree-level gluon propagator of the refined Gribov-Zwanziger (RGZ) decoupling type, whereas in the former it reduces to the massive FP/CF form, avoiding double counting of infrared scales by construction. A superspace derivation confirms that the induced horizon term originates from the ST superdeterminant, providing a microscopic mechanism for the emergence of the Gribov scale within the replica framework. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Torsion-Induced Modification to Friedmann Equations in $AdSL_{4}$ Gauged Gravity https://arxiv.org/abs/2603.02864 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02864v1 Announce Type: new Abstract: We study the solution of the gravitational field equations in $AdSL_{4}$-gauged gravity, a gauge-theoretic extension of general relativity based on the $AdSL_{4}$ algebra. In this formulation, the antisymmetric gauge field $B^{ab}$, associated with additional $AdSL_{4}$ tensorial generators, induces space-time torsion via the relation $K^{ab}=\mu B^{ab}$, where $K^{ab}$ denotes the contorsion 1-form. The presence of torsion modifies both the spin connection and curvature, leading to an extended set of Einstein-Cartan field equations. Focusing on spatially homogeneous and isotropic cosmological backgrounds, we derive the modified Friedmann equations which explicitly incorporate the torsional contribution. The resulting acceleration equation admits de Sitter-like solutions in which cosmic acceleration originates purely from the gauge-theoretic structure of enlarged four-dimensional space-time symmetries. Within this formulation, the dynamical components of the gauge field $B^{ab}$ emerge naturally as a source of the effective cosmological constants, without the introduction of exotic matter sources. Furthermore, our analysis shows that the torsion-driven cosmological phase in $AdSL_{4}$-gauged gravity can reproduce an effective equation-of-state parameter $\omega_{B}=-1/3$, establishing a connection between space-time torsion and cosmic-string-like dynamics. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Dimensional Reduction is Supersymmetric at Three Loops https://arxiv.org/abs/2603.02892 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02892v1 Announce Type: new Abstract: We resolve the long-standing claim that regularisation by dimensional reduction (DR) fails to preserve supersymmetry in Super Yang-Mills (SYM) theories at three loops. Earlier results reported a mismatch between the Yukawa and ghost-gluon $\beta$ functions in $\mathcal{N}=2$ SYM, suggesting a breakdown of supersymmertry. We show that this discrepancy does not originate from DR itself but from subtleties in the treatment of the Clifford algebra. A corrected three-loop calculation restores full supersymmetric behaviour, and we demonstrate that the same issue would first affect $\mathcal{N}=4$ SYM only at five loops, consistent with existing four-loop results. Our findings confirm that DR preserves supersymmetry for $\mathcal{N}=1, 2$ and $4$ SYM through the loop orders examined. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Evolution and scattering of excited topological defects: Interaction between internal modes https://arxiv.org/abs/2603.03003 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.03003v1 Announce Type: new Abstract: This thesis presents an extensive analysis of the behavior of topological solitons when one or more of their internal modes are activated. The first part of this manuscript is devoted to the study of the simplest topological solitons in (1+1) dimensions: kinks. Specifically, we investigate how these solutions emit radiation when one of their internal modes is initially excited, within the framework of the double $\phi^4$ model. The simplest kink solution in this theory exhibits a complex internal mode structure that depends on a coupling constant appearing in the potential governing the dynamics. We will show how the amplitude and frequency of the emitted radiation are affected by changes in this coupling constant. We also examine the dynamics of wobbling kink/antikink scattering when the kinks possess more than one internal mode. To this end, we study kink/antikink collisions in the context of the simplest kink solution arising in the MSTB model. This analysis sheds light on the resonant energy exchange mechanism, allowing energy transfer between internal modes and the translational mode. The second part of this thesis focuses on excited vortex solutions in (2+1) dimensions. We begin with a detailed study of the internal mode structure associated with vortex solutions in the Abelian-Higgs model. We demonstrate how the problem can be significantly simplified by choosing an appropriate angular dependence for the eigenfunctions. Furthermore, we investigate the radiation emitted by a vortex when its internal mode is initially activated. To achieve this, we extend the analytical techniques used in (1+1) dimensions to field theories defined in two spatial dimensions. This enables us to compute the radiation amplitude, its frequency, and the decay of the internal mode amplitude due to energy loss via radiation. All analytical results are contrasted with data from numerical simulations. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Spin Ruijsenaars-Schneider models are Coulomb branches https://arxiv.org/abs/2603.03048 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.03048v1 Announce Type: new Abstract: In this paper, we show that the Poisson algebras of cohomological and $K$-theoretic Coulomb branches of 3d $\mathcal{N}=4$ necklace quiver gauge theories provide Poisson structures and Hamiltonians that reproduce the equations of motion of the rational and hyperbolic spin Ruijsenaars-Schneider models, respectively. The construction is carried out in terms of monopole operators in the GKLO representation, also making the affine Yangian (and, in $K$-theory, quantum toroidal) superintegrability structure manifest. We conjecture that the Poisson algebras of elliptic Coulomb branches similarly reproduce the elliptic spin Ruijsenaars-Schneider model. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Beyond thresholds: reconstructing UV physics from IR expansions https://arxiv.org/abs/2603.03277 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.03277v1 Announce Type: new Abstract: We show that ultraviolet information can be extracted from low-energy expansion coefficients, assuming analyticity and the absence of massless singularities. By reorganizing the low-energy expansion through an inverse Laplace transform and a controlled coarse-graining procedure, we make ultraviolet behavior accessible beyond the cutoff of the effective field theory. In particular, we determine the sign of the beta function and the associated dynamical scale directly from the low-energy expansion of a physical observable below the mass thresholds in QED and QCD-like theories. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Series involving central binomial coefficients and higher-order harmonic numbers https://arxiv.org/abs/2602.12091 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2602.12091v2 Announce Type: cross Abstract: We derive modular parametrizations for certain infinite series whose summands involve central binomial coefficients and higher-order harmonic numbers. When the rates of convergence are certain rational numbers, modularity allows us to reduce the corresponding series to special values of the Dirichlet $L$-functions. For example, we establish the following identities conjectured by Sun:\[\sum_{k=0}^\infty\binom{2k}{k}^3\left[ \mathsf H_{2k}^{(2)}-\frac{25}{92}\mathsf H_{ k}^{(2)} +\frac{735L_{-7}(2)-86\pi^{2}}{1104}\right]\frac{1}{4096^{k}}=0,\]\[\sum_{k=0}^\infty\binom{2k}k^3\left[\mathsf H_{2k}^{(3)}-\frac{43}{352}\mathsf H_k^{(3)}\right]\frac{42k+5}{4096^k}=\frac{555\zeta(3)}{77\pi}-\frac{32G}{11},\] where $ \mathsf H^{(r)}_k:= \sum_{0<n\leq k}\frac{1}{n^r}$, $ L_{-7}(2):= \sum_{n=1}^\infty\left(\frac{-7}{n}\right)\frac{1}{n^2}=\frac{1}{1^2}+\frac{1}{2^2}-\frac{1}{3^2}+\frac{1}{4^{2}}-\frac{1}{5^{2}}-\frac{1}{6^{2}}+\frac{1}{8^{2}}+\cdots $, $ G:= \sum_{n=0}^\infty\frac{(-1)^n}{(2n+1)^2}$, and $ \zeta(3):= \sum_{n=1}^\infty\frac1{n^3}$. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Quantum regression theorem in the Unruh-DeWitt battery https://arxiv.org/abs/2603.02287 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02287v1 Announce Type: cross Abstract: In this paper, we employ the quantum regression theorem, a powerful tool in the study of open quantum systems, to analytically study the correlation functions of an Unruh-DeWitt detector, which is an uniformly accelerated two-level quantum system, absorbing charges from an external classical coherent pulse. The system can thus be viewed as a relativistic quantum battery that interacts with the environment of its perceived particles, namely, the quanta of a massless scalar field. By considering the relativistic battery moving in Rindler spacetime, under Born-Markov approximation, we derive the Gorini-Kossakowski-Sudarshan-Lindblad master equation governing the evolution of the system's reduced density matrix. Moreover, we perform the Fourier transformation of the Wightman functions and use exponential regularisation to compute the functional forms appearing in the master equation. Next, we derive the evolution equations for the the single-time expectation values of the system's operators. We not only solve these equations to find out the single time averages, but also employ the quantum regression theorem to determine the two-time correlation functions of first and second order. We analyse them in details to explain the phenomenon of spontaneous emission and show analytically how the acceleration can enhance the associated dissipation. Furthermore, we address a special form of second order correlation function relevant to the context of photon bunching arising in Bose-Einstein statistics. Finally, we derive the spontaneous emission spectrum of the battery detector analytically, which in the long-time limit displays a well-defined Lorentzian line shape in the high frequency regime. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Spin hydrodynamics on a hyperbolic expanding background https://arxiv.org/abs/2603.02296 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02296v1 Announce Type: cross Abstract: We study relativistic spin hydrodynamics on the hyperbolic $\kappa=-1$ flow background recently identified by Grozdanov. This background corresponds to an $SO(2,1)$-invariant, transversely expanding solution with finite spacetime support in Minkowski space, in contrast to the well-known Gubser flow $(\kappa=+1)$ which possesses $SO(3)$ symmetry and infinite transverse extent. Working within the formulation of perfect-fluid spin hydrodynamics, we derive the exact evolution equations for all spin components of the spin potential on the $\kappa=-1$ background. We find that the enhanced early-time expansion rate and the presence of a causal edge lead to a stronger localization of spin dynamics compared to the Gubser case. Remarkably, the azimuthal component of the spin potential oscillates as it decays in the forward lightcone, in stark contrast to the Gubser flow. Thus, our results establish the $\kappa=-1$ flow as a distinct and physically meaningful benchmark for studying spin dynamics in expanding relativistic fluids with finite spacetime support. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Collapse and transition of a superposition of states under a delta-function pulse in a two-level system https://arxiv.org/abs/2603.02407 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02407v1 Announce Type: cross Abstract: Under a time-dependent perturbation it is common to calculate the transition probability in going from from one eigenstate to another eigenstate of a quantum system. In this work we study the transition in going from a \textit{linear superposition of eigenstates} to an eigenstate under a delta-function pulse (which acts at $t=0$). We consider a two-level system with energy levels $E_1$ and $E_2$ and solve the coupled set of first order equations to obtain exact analytical expressions for the coefficients $c_1(t>0)$ and $c_2(t>0)$ of the final state. The expressions for the final coefficients are general in the sense that they are functions of the interaction strength $\beta$ and the coefficients $\alpha_1$ and $\alpha_2$ of the initial superposition state which are free parameters constrained only by $|\alpha_1|^2+ |\alpha_2|^2=1$. This opens up new possibilities and in particular, allows for a ``collapse" scenario. We obtain a general analytical expression for the transition probability $P_{\alpha_1,\alpha_2 \to 2}$ in going from an initial superposition state to the second eigenstate. Armed with this general expression we study some interesting special cases. With a delta-function pulse, the transitions are abrupt/instantaneous and we show that they do not depend on the energy gap $E_2-E_1$ and hence on the relative phase between the two eigenstates. For specific multiple values of the interaction strength $\beta$, we show that the system ends up in a definite eigenstate i.e. probability of unity. Such a transition can be viewed as a ``collapse" since a superposition of states transitions abruptly to a definite eigenstate. The collapse of the wavefunction is familiar in the context of a measurement. Here it occurs via a delta-function pulse in Schr\"odinger's equation. We discuss how this differs from a collapse due to a measurement. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Solving sign problems with physics-informed kernels https://arxiv.org/abs/2603.03159 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.03159v1 Announce Type: cross Abstract: In the present work we construct a novel generative architecture for systems with complex probability distributions. In general, these sampling tasks come with two challenges: resolving sign problems and efficient sampling. The architecture is based on physics-informed kernels (PIKs) introduced in arXiv:2510.26678, and aims at resolving both challenges. Key to the complex PIK-architecture is its probability-weight preserving property, which allows us to map the sampling task to one on a sign-problem free manifold with a simple distribution and efficient sampling. The potential of this novel architecture is demonstrated within applications to zero-dimensional field theories with complex couplings, as well as the real-time evolution of the quantum-mechanical harmonic oscillator. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Three-loop renormalization of the N=1, N=2, N=4 supersymmetric Yang-Mills theories https://arxiv.org/abs/0809.2509 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:0809.2509v3 Announce Type: replace Abstract: We calculate the renormalization constants of the N=1, N=2, N=4 supersymmetric Yang-Mills theories in an arbitrary covariant gauge in the dimensional reduction scheme up to three loops. We have found, that the beta-functions for N=1 and N=4 SYM theories are the same from the different triple vertices. This means that the dimensional reduction scheme works correctly in these models up to third order of perturbative theory. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Carroll black holes https://arxiv.org/abs/2308.10947 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2308.10947v4 Announce Type: replace Abstract: Despite the absence of a lightcone structure, some solutions of Carroll gravity show black hole-like behaviour. We define Carroll black holes as solutions of Carroll gravity that exhibit Carroll thermal properties and have a Carroll extremal surface, notions introduced in our work. The latter is a Carroll analogue of a Lorentzian extremal surface. As examples, we discuss the Carroll versions of Schwarzschild, Reissner-Nordstroem, and BTZ black holes and black hole solutions of generic 1+1 dimensional Carroll dilaton gravity, including Carroll JT and Carroll Witten black holes. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Gravitational back-reaction is magical https://arxiv.org/abs/2403.07056 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2403.07056v4 Announce Type: replace Abstract: We study the interplay between magic and entanglement in quantum many-body systems. We show that non-local magic, which is supported by the quantum correlations is lower bounded by the non-flatness of entanglement spectrum and upper bounded by the amount of entanglement in the system. We then argue that a smoothed version of non-local magic bounds the hardness of classical simulations for incompressible states. In conformal field theories, we conjecture that the non-local magic should scale linearly with entanglement entropy but sublinearly when an approximation of the state is allowed. We support the conjectures using both analytical arguments based on unitary distillation and numerical data from an Ising CFT. If the CFT has a holographic dual, then we prove that the non-local magic vanishes if and only if there is no gravitational back-reaction. Furthermore, we show that non-local magic is approximately equal to the rate of change of the minimal surface area in response to the change of cosmic brane tension in the bulk. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Collective Modes in Weyl Superconductors and the Axial Anomaly https://arxiv.org/abs/2505.12498 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2505.12498v4 Announce Type: replace Abstract: We develop a covariant Lagrangian formulation for a time reversal symmetry broken, minimally relativistic three dimensional Weyl superconductor that preserves continuous chiral invariance in the chiral limit. Within this framework, the FFLO pairing spontaneously breaks the axial $U(1)_A$ symmetry, giving rise to distinct collective excitations. Using the Nambu Jona Lasinio approach, we identify a pseudo scalar Nambu Goldstone mode (This mode is absent for conventional BCS internode pairing) that acquires a small mass under explicit chiral symmetry breaking and couples to gauge fields through the axial anomaly, closely analogous to the neutral pion decay in QCD. Although this anomaly induced decay is strongly suppressed in the bulk by the Meissner effect, it may occur via surface electromagnetic fields. Our analysis also predicts additional vector and axial vector collective modes associated with the broken $U(1)_A$ symmetry, providing a unified description of collective excitations in Weyl superconductors and their correspondence to mesonic modes in QCD. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) One loop in $D=11$ vs $D=10$: 4-point check https://arxiv.org/abs/2506.16391 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2506.16391v3 Announce Type: replace Abstract: The one-loop correction to eleven-dimensional supergravity involves a cubically divergent term $t_8t_8R^4$, with four Riemann tensors. A similar term (with finite coefficient) has been argued to be present in the M-theory effective action. It is expected to reduce to a similar one-loop term present in the type IIA effective action. This has previously been verified in the NSNS sector at the 4-point level. Here we extend this result to couplings of NSNS and RR fields, which have been computed using the pure spinor formalism. In particular, we check all couplings of RR fields to the dilaton as well as all couplings involving the metric and RR three-form. Correcting some minor mistakes in the literature we find complete agreement. We also give a complete analysis of 4-point terms in eleven dimensions computed previously from superparticle amplitudes and present a very simple form for these. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Nonconformally Ricci-flat instantons in Conformal Gravity with and without nonlinear matter fields https://arxiv.org/abs/2510.11854 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2510.11854v2 Announce Type: replace Abstract: In this work, we study nonconformally Ricci-flat gravitational instantons in four-dimensional Conformal Gravity, both in vacuum and in the presence of nonlinear conformal matter. First, the one-parameter extension of the Kerr-NUT-AdS metric is analyzed. We obtain their conserved charges by using the Noether-Wald formalism. It turns out that they receive corrections from the linear modes present in Conformal Gravity, which are properly identified. Then, we perform the analytic continuation into the Euclidean section and find the curve in parameter space along which this solution becomes regular and globally (anti)self-dual. Using the Dunajski-Tod theorem, we show that the self-dual metric is not conformally Ricci-flat. Then, the backreaction of nonlinear conformal matter is considered. In particular, we find new gravitational instantons in the presence of conformally coupled scalar fields and ModMax electrodynamics. We compute the partition function and conserved charges, which turn out to be finite by virtue of the conformal invariance of the theory. As a byproduct, we also obtain a generalization of the Riegert metric dressed with nonlinear conformal matter as a particular limit of these instantons. For all cases, we analyze the global properties, the curve in parameter space where the solutions are (anti)-self-dual, and the on-shell Euclidean action, among other features. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) From Quantum Relative Entropy to the Semiclassical Einstein Equations https://arxiv.org/abs/2510.24491 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2510.24491v3 Announce Type: replace Abstract: We provide arguments indicating that the semiclassical Einstein equations follow from quantum relative entropy and its proportionality to an area variation. Using modular theory, we establish that the relative entropy between the vacuum state and coherent excitations of a scalar quantum field on a bifurcate Killing horizon is given by the energy flux across the horizon. Under the assumption of the Bekenstein-Hawking entropy-area formula, this energy flux is proportional to a variation in the surface area of the horizon cross section. The semiclassical Einstein equations follow automatically from this identification. Our approach provides a quantum field theoretic generalization of Jacobson's thermodynamic derivation of the Einstein equations, replacing classical thermodynamic entropy with the well-defined quantum relative (Araki-Uhlmann) entropy. This suggests that quantum information plays a central role in what is often seen as a zeroth order approximation of a theory of quantum gravity, namely quantum field theory in curved spacetimes. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) From BTZ Perturbations to Schwarzian Modes: A Geometrical and Perturbative Analysis https://arxiv.org/abs/2511.07111 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2511.07111v3 Announce Type: replace Abstract: We provide a detailed derivation of the Schwarzian modes in the full geometry of the Ba\~nados-Teitelboim-Zanelli (BTZ) black hole at finite temperature, establishing the precise conditions under which they emerge from the general solution, thereby clarifying the absence of rotational modes in the full geometry. In addition, we demonstrate that the same modes can be recovered through a purely geometric Kerr-Schild construction. This equivalent approach offers a new geometric understanding of the Schwarzian sector and highlights the correspondence between perturbative and pure geometric approaches, additionally it provides a connection with double copy. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Hamilton Revised: The Action Principle for Initial Value Problems https://arxiv.org/abs/2603.02350 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02350v1 Announce Type: cross Abstract: We present the variational action principle for initial value problems in classical, conservative-force point particle mechanics. We rigorously derive this formulation by taking the classical limit of the Schwinger-Keldysh expression for the time dependence of the expectation value for operators in quantum mechanics. We clarify the connection between the variation of the position and the variation of the velocity of a particle when implementing Hamilton's Principle in deriving the Euler-Lagrange Equations. We show that both the plus and minus Keldysh paths (of the average and difference of the forward/backward paths) have classical paths and fluctuations -- unlike the common perception that the minus path provides the fluctuations around the single classical solution given by the plus path -- and that the fluctuations of both paths are crucial for the correct normalization of the classical limit. The classical limit yields "initial conditions" and equations of motion for the minus paths such that the unique classical solution for the minus paths is that they are identically zero, and, fascinatingly, that the minus paths' solution propagates backwards in time; thus one does not need to set the minus paths to zero by hand when taking the classical limit of the Schwinger-Keldysh formalism. We note implications for the classical and quantum mechanics of non-holonomic constraints and quantum field theories with gauges dependent on the derivatives of the fields. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) The multiloop sunset to all orders https://arxiv.org/abs/2603.03183 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.03183v1 Announce Type: new Abstract: We derive exact, convergent representations of multiloop sunset Feynman integrals in two dimensions for arbitrary mass configurations and all loop orders valid for large Euclidean momentum. The integrals are expressed as sums of symmetric polynomials in logarithmic mass ratios, normalized by the external momentum squared, with coefficients determined by analytic series expansions. For the equal-mass case, we establish a dimension-raising relation expressing the $L$ loop sunset integrals in $D+2$ as the one in $D$ dimensions acted on a differential operator of order $L-1$. These representations are free of complicated transcendental functions, making them well-suited to both formal analysis and high-precision numerical evaluation. The two-dimensional results serve as boundary conditions for dimension-shifting relations, enabling systematic reconstruction of four-dimensional sunset integrals via analytic continuation to $D = 4 - 2\epsilon$. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Data Unfolding: From Problem Formulation to Result Assessment https://arxiv.org/abs/2603.03168 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.03168v1 Announce Type: cross Abstract: Experimental data in particle and nuclear physics, particle astrophysics, and radiation protection dosimetry are collected using experimental facilities that consist of a complex system of sensors, electronics, and software. Measured spectra or cross sections are considered as Probability Density Functions (PDFs) that deviate from true PDFs due to resolution, bias, and efficiency effects. Unfolding is viewed as a procedure for estimating an unknown true PDF. Reliable estimates of the true PDF are necessary for testing theoretical models, comparing results from different experiments, and combining results from various research endeavors. Both external and internal quality assessment methods can be applied for this purpose. In some cases, external criteria exist to evaluate deconvolution quality. A typical example is the deconvolution of a blurred image, where the sharpness of the restored image serves as an indicator of quality. However, defining such external criteria can be challenging, particularly when a measurement has not been performed previously. This paper discusses various internal criteria for assessing the quality of the results independently of external information, as well as factors that influence the quality of the unfolded distribution. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Improved Binary Black Hole Search Discriminator from the Singular Value Decomposition of Non-Gaussian Noise Transients https://arxiv.org/abs/2507.04628 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2507.04628v2 Announce Type: replace Abstract: The sensitivity of current gravitational wave (GW) detectors to transient GW signals is severely affected by a variety of non-Gaussian and non-stationary noise transients, such as the blip, tomte, koi fish, and low-frequency blip 'glitches'. These glitches share some time-frequency resemblance with GW signals from binary black holes. In earlier works [Joshi et al., Phys. Rev. D 103, 044035 (2021); Choudhary et al., Phys. Rev. D 110, 044051 (2024)], the authors presented a method for constructing a $\chi^2$-distributed optimized statistic, based on the unified formalism of $\chi^2$ discriminators [Dhurandhar et al., Phys. Rev. D 96, 103018 (2017)], to distinguish the blip glitches from the compact binary coalescence (CBC) signals. Unlike past works, the new $\chi^2$ discriminator is constructed from the most significant singular vectors obtained from the singular value decomposition of different classes of glitches in real detector data. We find that the chi-square developed in this work performs as efficiently as in Choudhary et al. [Phys. Rev. D 110, 044051 (2024)], which used sine-Gaussian basis vectors. This result supports past empirical findings that these glitches are reasonably well-modeled by sine-Gaussians. It also introduces a method for constructing signal- and glitch-based $\chi^2$ discriminators by directly using real data containing the glitches and, thus, holds promise for extensions to glitches that are captured less well by sine-Gaussians or other analytical functions. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Perturbative semiclassical entropy of dynamical black holes https://arxiv.org/abs/2603.02320 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02320v1 Announce Type: cross Abstract: We consider perturbative quantum gravity as a quantum field theory of linearized metric perturbation on an asymptotically flat spacetime with a bifurcate Killing horizon. We include the perturbative gravitational constraints into the algebra of observables restricted to the right half of the future horizon of the spacetime. We use the boundary charge, associated to the horizon Killing field, as an auxiliary "observer" degree of freedom. The observables "dressed" with the additional charge are invariant under the Killing symmetry and generate a Type-$\text{II}_{\infty}$ von Neumann factor. We compute the von Neumann entropy of the reduced density matrix of a classical-quantum coherent state constructed from the metric perturbations and the "observer wavefunction". This von Neumann entropy satisfies an analogue of the first law of thermodynamics. We further show that this entropy is related to Hollands-Wald-Zhang entropy of the (second order) perturbed dynamical black hole through the flux of perturbations through the horizon and future null infinity. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Geodesic flows on a black-hole background https://arxiv.org/abs/2603.03222 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.03222v1 Announce Type: new Abstract: A recent notion of geodesic flows which comes out of noncommutative geometry but which is also novel in the classical case is studied in detail for a Schwarzschild spacetime. In this framework, the geodesic velocity field is an independent concept which then defines the flow of a density $\rho$ on spacetime or possibly that of an amplitude wave function $\psi$ with $\rho = |\psi|^2$. The proper time flow parameter $s$ is generated collectively by the flow of matter. We show carefully how the $\rho$ evolution can be justified as modelling a large number of geodesics interpolated as a local density. Using Kruskal-Szekeres coordinates, we show that there are no issues crossing the horizon. A novel feature is that whereas two colliding Gaussian bumps in density $\rho$ merge into a single bump, two colliding wave function $\psi$ bumps of opposite phase merge into a dipole with a different density $|\psi|^2$ profile, providing a potential test of our wave-function hypothesis. We also revisit the Klein-Gordon flow or pseudo-quantum mechanics around a black-hole and find that previously found black-hole atom states and modes generated at the horizon when an area of disturbance approaches it are also present inside the black-hole in a reflected fashion. We argue that the behaviour of the horizon modes across the horizon as well as discretisation of the atomic spectrum depend on quantum gravity corrections at the horizon. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Global existence for a Fritz John equation in expanding FLRW spacetimes https://arxiv.org/abs/2603.02307 Wed, 04 Mar 2026 00:00:00 -0500 arXiv:2603.02307v1 Announce Type: new Abstract: We study the family of semilinear wave equations $\square_{\mathbf{g}_p}\phi=(\partial_t\phi)^2$, on fixed expanding FLRW spacetimes, having $\mathbb{R}^3$ spatial slices and undergoing a power law expansion, with scale factor $a(t)=t^p$, $0 1$) and relied on the integrability of the inverse of the scale factor to establish future global well-posedness. In the current work, where such an integrability condition is lacking, we rely on a vector field method that captures and combines dispersive estimates with the spacetime expansion to control the solution and suppress the nonlinear blow-up mechanism. To achieve this, we commute the Laplace-Beltrami operator with a boosts-free subset of the Poincar\'e algebra and employ Klainerman-Sideris types of inequalities. Our strategy is general and is developed to handle the non-stationary nature of FLRW spacetimes. While we focus solely on this Fritz John type of equation, which serves as a prototype to study blow-up of non-linear waves, our approach provides a rigorous proof of the regularizing effects of spacetime expansion and can be exploited for a wider range of applications and nonlinearities. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Deep Learning-Based $^{14}$C Pile-Up Identification in the JUNO Experiment https://arxiv.org/abs/2603.01419 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01419v1 Announce Type: new Abstract: Measuring neutrino mass ordering (NMO) poses a fundamental challenge in neutrino physics. To address this, the Jiangmen Underground Neutrino Observatory (JUNO) experiment is scheduled to commence data collection in late 2024, with the ambitious goal of determining the NMO at a 3-sigma confidence level within a span of 6 years. A key factor in achieving this is ensuring a high-quality energy resolution of positrons. However, the presence of residual $^{14}$C isotopes in the liquid scintillator introduces pile-up effects that can impact the positron energy resolution. Mitigating these pile-up effects requires the identification of pile-up events, which presents a significant challenge. The signal from $^{14}$C is considerably smaller compared to the positron signal, making its identification difficult. Additionally, the close event time and vertex between a positron and a $^{14}$C further compound the identification challenge. This contribution focuses on the application of deep learning models for the identification of $^{14}$C pile-up events. It encompasses a range of models, including convolution-based models and advanced transformer models. Through performance evaluation, it shows the deep learning-based methods is promising to identify the pile-up events. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Search for the charmonium weak decay $\psi(2S)\to D_s^-\pi^+ + c.c.$ and $\psi(2S)\to D_s^-\rho^+ + c.c.$ https://arxiv.org/abs/2603.01777 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01777v1 Announce Type: new Abstract: We search for the weak decays $\psi(2S)\to D_s^-\pi^+ + c.c.$ and $\psi(2S)\to D_s^-\rho^+ + c.c.$ for the first time. The search is based on $(2712.4\pm14.3)\times 10^6$ events containing the charmonium state $\psi(2S)$ collected at the center-of-mass energy $\sqrt{s}=3.686\ \rm{GeV}$ with the BESIII detector. This search offers a unique opportunity to test the Standard Model and search for new physics. Since no signal excess above the background is observed, the upper limits on the branching fractions at the 90\% confidence level are set to be $1.4\times 10^{-6}$ and $7.0\times 10^{-6}$ for $\psi(2S)\to D_s^-\pi^+ + c.c.$ and $\psi(2S)\to D_s^-\rho^+ + c.c.$, respectively. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Absolute scintillator light yield correction for SiPIN readout via Transfer Matrix Method and Geant4 optical simulation https://arxiv.org/abs/2603.01867 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01867v1 Announce Type: new Abstract: Precise measurement of the absolute light yield (LY) of scintillators has long been limited by systematic effects inherent in realistic readout geometries. Large-angle incidence, multiple reflections inside the optical housing, and refractive-index mismatch at the coupling interface all introduce biases that cannot be removed by a simple conversion based on the detector's nominal quantum efficiency. To address this problem, we present a correction method that combines the Transfer Matrix Method (TMM) with Geant4 optical Monte Carlo simulation. A wave-optics model of the SiPIN surface thin-film stack is used to extract the angle- and wavelength-dependent single-hit detection probability $p_{\mathrm{det}}(\lambda,\theta)$, which is then dynamically coupled into the macroscopic photon transport simulation, achieving a full-chain integration of the microscopic interface optical response with macroscopic geometric light collection. We demonstrate the method using a GAGG:Ce crystal as the test sample. Two types of optical housings -- a high-absorption Absorber and a high-reflection Reflector -- are each combined with air and optical-grease coupling, forming four independent configurations whose overall photon-to-signal conversion efficiencies $\alpha_{\mathrm{SiPIN}}$ span more than a factor of three. Despite the very different optical boundaries, the intrinsic light yields derived from the four configurations show excellent mutual consistency (coefficient of variation $= 1.8\%$). The measured intrinsic light yield of GAGG:Ce is $LY_{\mathrm{int}} = (5.63 \pm 0.10_{\mathrm{spread}} \pm 0.16_{\mathrm{syst}}) \times 10^{4}~\mathrm{ph/MeV}$. The correction framework effectively decouples the systematic influence of complex geometry and interface optics from photon detection, providing a general-purpose scheme for high-precision, traceable scintillator characterization. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Search for massive, long-lived particles in events with displaced vertices and displaced muons in $pp$ collisions at $\sqrt{s}=13.6$ TeV with the ATLAS experiment https://arxiv.org/abs/2603.01991 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01991v1 Announce Type: new Abstract: A search is presented for massive long-lived particles in events featuring at least one displaced vertex and at least one displaced muon, using proton-proton collision data collected by the ATLAS detector at the Large Hadron Collider from 2022 to 2024 at a centre-of-mass energy of 13.6 TeV. The data sample corresponds to an integrated luminosity of 164 fb$^{-1}$. The analysis targets scenarios in which long-lived particles decay inside the ATLAS inner detector, resulting in a topology of at least one massive, displaced vertex (DV) with multiple associated tracks, and at least one muon with a large transverse impact parameter relative to the primary interaction point. The muon is not required to be associated with the DV. Two signal regions are defined by the transverse distance of the reconstructed DV from the interaction point. Background contributions are estimated by using fully data-driven techniques. No significant excess above the expected background is observed. Upper limits at 95% confidence level are set on the visible cross-section and on the production cross-sections of several benchmark models of $R$-parity-violating supersymmetry. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Conceptual Design of a Novel Highly Granular Crystal Electromagnetic Calorimeter for Future Higgs Factories https://arxiv.org/abs/2602.09836 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2602.09836v1 Announce Type: cross Abstract: Next-generation high-energy electron-positron colliders, operating as Higgs factories, require an unprecedented jet energy resolution for precision measurements of Higgs and Z/W bosons. To address this challenge, a conceptual design is presented for a novel high-granularity crystal electromagnetic calorimeter that combines the superior intrinsic energy resolution of a homogeneous calorimeter with the fine segmentation required for particle-flow reconstruction. The crystal electromagnetic calorimeter design is based on orthogonally arranged long scintillating crystal bars read out by silicon photomultipliers (SiPMs) at both ends. Key design specifications were established through comprehensive simulation studies. Critical technical considerations, including crystal choices, photosensors, electronics, mechanical support, and radiation damage, are discussed. A dedicated digitisation framework was developed to realistically model effects from the crystal, SiPMs, and readout electronics. The performance of a single calorimeter module was evaluated using simulated electron showers. Simulation results for a single module demonstrate an excellent electromagnetic energy resolution of $1.12\%/\sqrt{E(\mathrm{GeV})}\oplus0.24\%$ and an energy linearity within $\pm0.5\%$ for electrons from 3 GeV to 100 GeV. The performance significantly exceeds the design requirement of $\leq 3\%/\sqrt{E(\mathrm{GeV})}\oplus1\%$. The results establish the feasibility of the proposed high-granularity crystal calorimeter concept and point to a promising pathway toward the precision calorimetry required for future high-energy electron-positron collider experiments. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Search for Light Dark Sectors Using Electron-Photon Collisions https://arxiv.org/abs/2603.00247 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00247v1 Announce Type: cross Abstract: The dark photon is a new gauge boson that naturally arises in many beyond the Standard Model theoretical models, featuring interactions that resemble quantum electrodynamics. Due to this feature, it is often considered the portal between dark and visible sectors. For this reason, it has become the target of many experimental searches worldwide. In this work, we propose a search for dark photons based on the Inverse Compton scattering, $\gamma e^- \rightarrow A^\prime e^-$, to be conducted at electron accelerators. In this setup, photons from a laser source would impinge on the accelerated electron beam, producing a dark photon in the final state. We propose an experimental setup to take advantage of the photon counting technique, and we derive the projected sensitivity by considering the energy of the incident photon to be about 1 eV and an electron beam of 3 GeV. We show that this experimental setup could cover an unexplored region of parameter space and constitute a promising probe for dark sectors in the future. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) BSM Searches at a Photon Collider with Energy $E_{\gamma\gamma}< 12$ GeV https://arxiv.org/abs/2603.00264 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00264v1 Announce Type: cross Abstract: The possibility of a photon collider extension to the beam dump of the $17.5$ GeV European XFEL has already been discussed before as the first high energy collider of its sort. It would not only be the first proof of concept and test of a photon collider but would also be a collider without competition in the region of $E_{\gamma\gamma}=5-12$ GeV for photon-photon collision. In this range, $b\bar{b}$ and $c\bar{c}$ resonances, tetraquarks and mesonic molecules can be observed. Furthermore, some BSM processes can also be reached in this range. In this paper we want to discuss the possibility of observing ALPs in the process of light-by-light scattering at such a collider. We will use a simplified description of the Compton backscattering process to get a first look at cross sections for the Standard Model light-by-light scattering and the extension including ALPs. Furthermore, we extend this to the full beam dynamics included prediction, discuss all effects that are important when working with a photon collider and show that the photon collider with energy $E_{\gamma\gamma}<12$ GeV would offer an extended physics reach compared to current limits. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Physics Opportunities with a Fixed-Target Program at the Electron-Ion Collider https://arxiv.org/abs/2603.00265 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00265v1 Announce Type: cross Abstract: A fixed-target program at the Electron-Ion Collider (EIC) would broaden the facility's scientific reach by providing key measurements for studies of cold nuclear matter (CNM), the QCD phase diagram, and nuclear reactions relevant for space radiation. Constraining CNM effects is essential for interpreting observables in proton-nucleus ($p+A$) and nucleus-nucleus ($A+A$) collisions, yet these effects are poorly understood at low center-of-mass energies. In particular, the range $\sqrt{s}\approx10$--20 GeV, where several CNM effects may compete at similar scales, has not been explored with high statistical precision. Mapping the QCD phase diagram similarly requires high-statistics $A+A$ data with broad rapidity and transverse-momentum coverage to probe the onset of deconfinement and the possible location of the QCD critical point (CP). Currently, such data are limited at 4.5 GeV $< \sqrt{s_{NN}} < 7.7$ GeV A fixed-target program at the EIC would fill these gaps, providing CNM baselines and complementary data for QCD CP studies. By delivering high luminosity and systematic measurements across a broad range of nuclear targets, the program would link $p+A$ and $A+A$ systems at the same center-of-mass energies, enabling a unified, quantitative description of cold QCD matter and clarifying the interpretation of QGP signatures in $A+A$ collisions at low energies where comparable $p+A$ data are lacking. Finally, the program would offer a unique opportunity to measure nuclear cross sections critical for improving cosmic-ray models, including studies of space-radiation protection for both autonomous spacecraft and long-duration human spaceflight. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Testing light and heavy vector mediators with solar CE$\nu$NS measurements https://arxiv.org/abs/2603.00554 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00554v1 Announce Type: cross Abstract: The recent observation of coherent elastic neutrino-nucleus scattering from solar $^8$B neutrinos in dark matter direct detection experiments has inaugurated the \emph{neutrino fog} era, highlighting the extended potential of these experiments as precision neutrino observatories. Recent measurements by the XENONnT, PandaX-4T, and LUX-ZEPLIN experiments provide new opportunities to test Standard Model predictions and to probe physics beyond it, in complementarity with dedicated neutrino facilities. We perform a combined analysis of nuclear recoil data from these three facilities to extract information on the solar $^8$B neutrino flux normalization and on the weak mixing angle at low-momentum transfer. We further investigate the impact of new vector interactions on the solar neutrino event rate, deriving constraints on nonstandard neutrino interactions and on scenarios with light vector mediators. Our results demonstrate that dark matter detectors are rapidly becoming complementary to terrestrial neutrino experiments in probing neutrino interactions, and already set competitive bounds on both light and heavy vector mediators. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Precise Measurement and Control of Radon Progeny on Detector Surfaces https://arxiv.org/abs/2603.00647 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00647v1 Announce Type: cross Abstract: In low-background particle physics experiments, surface deposition of radon progeny presents a significant background challenge. To characterize this contamination, a high-sensitivity surface $\alpha$-activity measurement system was developed, which employs a 3$\times$3 Si-PIN array operating in vacuum to perform $\alpha$-spectroscopy on samples. The system was calibrated using Poly(Methyl MethAcrylate) (PMMA) plates exposed to a controlled high-radon atmosphere, achieving an energy resolution of 2.09 \% for 5.30~MeV $\alpha$ particles and a one-day measurement sensitivity of 1.27~$\mu$Bq/cm$^2$ for $^{210}$Po surface activity. Using this system and a self-built high radon concentration chamber, the deposition behavior of radon progeny on PMMA surfaces was investigated. Results indicate a non-monotonic dependence on exposure time, a significant enhancement of deposition with increasing negative surface electrostatic potential, and a strong modulation by ambient humidity. This paper details the apparatus design, calibration, and experimental study of radon progeny deposition dynamics on PMMA surfaces. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Midterm Status Report of the ILC Technology Network Activities https://arxiv.org/abs/2603.01172 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01172v1 Announce Type: cross Abstract: The ILC Technology Network (ITN) was established in 2022 by the ILC International Development Team, a subcommittee of the International Committee for Future Accelerators, to advance engineering studies toward the realisation of the International Linear Collider (ILC). While the ITN work packages focus on engineering activities for the ILC, their topics are also relevant to a broad range of accelerator applications in particle physics and beyond. These work packages are being carried out now by laboratories in Asia and Europe in close collaboration. This report summarises the current status of the ITN activities. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Naturalness and Fisher Information https://arxiv.org/abs/2603.01411 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01411v1 Announce Type: cross Abstract: Fine-tuning and naturalness, the sensitivity of low-energy observables to small changes in the fundamental parameters of a theory, are cornerstones of physics beyond the Standard Model. We propose a new measure of fine-tuning based on information theory. To each point in parameter space we associate a probability distribution over observables. Divergence measures encode the sensitivity of observables to model parameters and determine a Riemannian metric on parameter space. By Chentsov's theorem, the physically motivated metric is the Fisher information metric, up to scaling. We propose a rescaled fine-tuning matrix $\mathcal{F}_{ij}$ derived from the Fisher information matrix, whose non-zero eigenvalues serve as our measure of fine-tuning. When the number of observables exceeds the number of parameters, $\mathcal{F}_{ij}$ admits a natural geometric interpretation as the pullback of the Euclidean metric from observable space to the submanifold of admissible predictions, with large eigenvalues corresponding to highly stretched directions and indicative of fine-tuning. Our measure reproduces the familiar Barbieri--Giudice criterion as a special case, while generalising it to multiple correlated parameters. We illustrate its behaviour on dimensional transmutation, the Wilson--Fisher fixed point, a simple model of the hierarchy problem, and the electron Yukawa coupling, finding agreement with physical intuition in each case. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Effective degrees of freedom, trace anomaly and c-theorem like condition in the hadron resonance gas model https://arxiv.org/abs/2603.02085 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.02085v1 Announce Type: cross Abstract: The relation between the effective degrees of freedom (EDOF) and the trace anomaly is studied in the hadron resonance gas (HRG) model. If we regard the thermodynamical relation as the evolution equation and define the EDOF as P/T^4, where P and T are the pressure and the temperature, respectively, we obtain the equation which relates to the trace anomaly. The structure of the equation resembles that of the so called c-theorem in the two dimensional conformal field theory which asserts that the EDOF should not increase as the energy scale parameter decreases. There is a stationary point where the trace anomaly (modified trace anomaly) vanishes, and the scale symmetry is restored. To investigate the limiting temperature of the HRG model with the excluded volume effects, we consider two types of the c-theorem like conditions for the EDOF. The first condition requires that the EDOF should not decrease when T increases. This condition is equivalent to the condition that the trace anomaly (modified trace anomaly) should not be negative. The second condition requires that the EDOF should be convex downwards as a function of T. It is found that the first condition gives the limiting temperature of the HRG model with the excluded volume effect which is much higher than the crossover transition temperature obtained by the lattice QCD calculation and, at zero baryon number density, is close to the transition temperature in the pure gluonic theory, while the second one gives the limiting temperature which almost coincides with the one obtained by using the normalized baryon number fluctuation in the previous work and is consistent with the critical point predicted by the lattice QCD calculation. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Sensitivity to sub-GeV dark matter in forthcoming spallation-source neutrino experiments https://arxiv.org/abs/2603.02132 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.02132v1 Announce Type: cross Abstract: Sub-GeV thermal dark matter weakly interacting with the Standard Model through vector-portal mediators provides a well-motivated and predictive framework that remains challenging to probe with conventional direct detection experiments. Motivated by the rapid development of neutrino facilities based on spallation neutron sources, we study the sensitivity of future coherent elastic neutrino-nucleus scattering experiments to light dark matter produced in neutral pion decays. We consider scalar dark matter interactions mediated by two different vector portals, a generic dark photon and a baryophilic vector mediator. The neutral pion yield is calculated through a GEANT4 simulation and the results are compared with those obtained with the Sandford-Wang parametrization. We show that predictions based on either approach do not produce significant differences. Our results demonstrate that upcoming low-threshold neutrino detectors at the European Spallation Source (ESS), the Japan Proton Accelerator Research Complex (J-PARC) and the China Spallation Neutron Source (CSNS) will test regions in parameter space not yet explored. We point out that these facilities will strengthen the global experimental program searching for secluded sectors. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Study of the $f_{0}(980)$ and $f_{0}(500)$ Scalar Mesons through the Decay $D_{s}^{+} \to \pi^{+} \pi^{-} e^{+} \nu_{e}$ https://arxiv.org/abs/2303.12927 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2303.12927v2 Announce Type: replace Abstract: Using $e^+e^-$ collision data corresponding to an integrated luminosity of 7.33~${\rm fb^{-1}}$ recorded by the BESIII detector at center-of-mass energies between 4.128 and 4.226~${\rm GeV}$, we present an analysis of the decay $D_{s}^{+} \to \pi^{+}\pi^{-} e^{+}\nu_{e}$, where the $D_s^+$ is produced via the process $e^+e^- \to D_{s}^{*\pm}D_{s}^{\mp}$. We observe the $f_{0}(980)$ in the $\pi^+\pi^-$ system and the branching fraction of the decay $D_{s}^{+} \to f_{0}(980)e^{+}\nu_{e}$ with $f_0(980)\to\pi^+\pi^-$ measured to be $(1.72 \pm 0.13_{\rm stat} \pm 0.10_{\rm syst}) \times10^{-3}$, where the uncertainties are statistical and systematic, respectively. The dynamics of the $D_{s}^{+} \to f_{0}(980)e^{+}\nu_{e}$ decay are studied with the simple pole parametrization of the hadronic form factor and the Flatt\'e formula describing the $f_0(980)$ in the differential decay rate, and the product of the form factor $f^{f_0}_{+}(0)$ and the $c\to s$ Cabibbo-Kobayashi-Maskawa matrix element $|V_{cs}|$ is determined for the first time to be $f^{f_0}_+(0)|V_{cs}|=0.504\pm0.017_{\rm stat}\pm0.035_{\rm syst}$. Furthermore, the decay $D^+_s\to f_0(500) e^+\nu_e$ is searched for the first time but no signal is found. The upper limit on the branching fraction of $D^+_s\to f_0(500) e^+\nu_e,~f_0(500)\to\pi^+\pi^-$ decay is set to be $3.3 \times 10^{-4}$ at 90\% confidence level. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Precise measurement of the $t\bar{t}$ production cross-section and lepton differential distributions in $e\mu$ dilepton events from $\sqrt{s}=13$ TeV $pp$ collisions with the ATLAS detector https://arxiv.org/abs/2509.15066 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2509.15066v2 Announce Type: replace Abstract: The inclusive top quark pair ($t\bar{t}$) cross-section $\sigma_{t\bar{t}}$ has been measured in $\sqrt{s}=13$ TeV proton-proton collisions, using 140 fb$^{-1}$ of data collected by the ATLAS experiment at the Large Hadron Collider. Using events with an opposite-charge $e\mu$ pair and $b$-tagged jets, the cross-section is measured to be: $\begin{equation}\nonumber \sigma_{t\bar{t}} = 829.3 \pm 1.3\,\mathrm{(stat)}\ \pm 8.0\,\mathrm{(syst)}\ \pm 7.3\,\mathrm{(lumi)}\ \pm 1.9\,\mathrm{(beam)}\,\mathrm{pb}, \end{equation}$ where the uncertainties reflect the limited size of the data sample, experimental and theoretical systematic effects, the integrated luminosity, and the proton beam energy, giving a total uncertainty of 1.3%. The result is used to determine the top quark pole mass via the dependence of the predicted cross-section on $m_t^\mathrm{pole}$, giving $m_t^\mathrm{pole}=172.8^{+1.5}_{-1.7}$ GeV. The same event sample is used to measure absolute and normalised differential cross-sections for the $t\bar{t}\rightarrow e\mu\nu\bar{\nu}b\bar{b}$ process as a function of single-lepton and dilepton kinematic variables. Complementary measurements of $e\mu b\bar{b}$ production, treating both $t\bar{t}$ and $Wt$ events as signal, are also provided. Both sets of differential cross-sections are compared to the predictions of various Monte Carlo event generators, demonstrating that the state-of-the-art generators Powheg MiNNLO and Powheg $bb4l$ describe the data better than Powheg hvq. The sensitivity of some of the measured differential distributions to quasi-bound-state formation near the $t\bar{t}$ threshold is investigated in an addendum. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Observation of tWZ production at the CMS experiment https://arxiv.org/abs/2510.19080 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2510.19080v2 Announce Type: replace Abstract: The first observation of single top quark production in association with a W and a Z boson in proton-proton collisions is reported. The analysis uses data at center-of-mass energies of 13 and 13.6 TeV recorded with the CMS detector at the CERN LHC, corresponding to a total integrated luminosity of 200 fb$^{-1}$. Events with three or four charged leptons, which can be electrons or muons, are selected. Advanced machine-learning algorithms and improved reconstruction methods, compared to an earlier analysis, result in an unprecedented sensitivity to tWZ production. The measured cross sections for tWZ production are 248 $\pm$ 52 fb and 242 $\pm$ 77 fb for $\sqrt{s}$ = 13 and 13.6 TeV, respectively. The signal is established with a statistical significance of 5.8 standard deviations, with 3.5 expected, compared to the background-only hypothesis. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Preliminary study of the $H$ dibaryon in $N_{\rm f}=2+1$ lattice QCD https://arxiv.org/abs/2603.00698 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00698v1 Announce Type: new Abstract: We present preliminary results on the $I=0$, $S=-2$ $H$ dibaryon in $N_{\rm f}=2+1$ QCD. The calculation is performed with heavier-than-physical quarks ($m_\pi \approx 280$ MeV) on a single CLS ensemble. Correlation matrices are constructed using the distillation technique and the three relevant channels, $\Lambda\Lambda$, $N\Xi$, $\Sigma\Sigma$, are investigated to determine the interacting spectrum relevant for $S$-wave across multiple momentum frames. The scattering amplitude is determined by solving the corresponding two-body quantization condition. These preliminary results are part of the ongoing efforts to determine the properties of di-hyperons and to establish whether the $H$ dibaryon exists down to physical quark masses. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Lattice artifacts proportional to the quark mass in the QCD running coupling https://arxiv.org/abs/2603.00753 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00753v1 Announce Type: new Abstract: Discretization artifacts proportional to the quark mass can limit the precision of strong-coupling determinations in lattice QCD, especially in the presence of heavy quarks. In this work, we perform a lattice perturbative analysis of such $\mathcal{O}(a m)$ effects in the running coupling by computing its two-loop renormalization factor $Z_g$. Using the background field method together with clover-improved Wilson fermions and Symanzik-improved gauge actions, we determine the mass-dependent components of the relevant two-point Green's functions and obtain the improvement coefficients needed to remove $\mathcal{O}(a m)$ artifacts in mass-independent renormalization schemes. Our results are presented for general values of the number of colors $N_c$, the number of quark flavors $N_f$, and the clover coefficient $c_{\mathrm sw}$, and satisfy all symmetry and consistency constraints. Numerical values are provided for widely used instances of the above gauge actions, allowing improved control of mass-related cutoff effects in high-precision determinations of the strong coupling constant from lattice QCD. Full derivations and extended numerical results can be found in Ref. [arXiv:2503.00463]. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) A novel framework for spectral density reconstruction via quadrature-based Laplace inversion https://arxiv.org/abs/2603.00764 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00764v1 Announce Type: new Abstract: In this work, we explore a numerical approach for performing the inverse Laplace transformation, with an emphasis on achieving stability and robustness under noisy conditions. Our quadrature-based method integrates reparameterization, data smoothing, and optimization techniques to regularizing ill-conditioned systems. Together, these elements enable consistency checks that enhance the reliability of the inversion process. Through a series of controlled tests on toy models, we demonstrate the stability and effectiveness of the method in the presence of noise. Using mock data, we approximate spectral densities from Euclidean correlators, generating smoothed and stable results that accurately reproduce the correlator behavior, particularly at large Euclidean times. We conclude by discussing prospects for applications to actual lattice QCD data. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) No Quantum Utility from Hadron Masses? No, Quantum Utility from Hadron Masses! https://arxiv.org/abs/2603.00946 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00946v1 Announce Type: new Abstract: Is there a quantum utility in establishing the masses of hadrons? Here we show that the best response is that of Farr\'es, Cap\'o, and Davis: perhaps, perhaps, perhaps. This is interesting given the general case that particle physics demands quantum computers. For stable hadrons, classical LQCD has achieved sub-percent precision with no sign problem, and quantum computers offer no advantage. For resonances, the Maiani-Testa theorem is an obstruction that quantum simulation is immune to. For nuclei, Wick contractions and signal-to-noise are genuine classical barriers. Underlying these cases is a unified picture connecting the sign problem to Wigner negativity and T gate cost. This manuscript was drafted from extensive interaction with \textsc{Claude}. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) $T_{cc}$ pole trajectory https://arxiv.org/abs/2603.01259 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01259v1 Announce Type: new Abstract: We investigate the spectrum of doubly charmed tetraquark $T_{cc}$ with quantum number $I(J^P) = 0(1^+)$ using MILC's $N_f = 2+1+1$ HISQ gauge ensembles at two lattice spacings. We have included diquark-antidiquark operator together with molecular and scattering operators in our analysis and varied both the heavy and light quark masses. We employ the anisotropic Clover action for heavy quarks, and $O(a)$-improved Wilson--Clover action for the light (up/down) quarks. In order to handle the non-analyticity near the Left Hand Cut we use modified L\"uschers method when close to it. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Lattice QCD study on nucleon-$\Omega_{\rm ccc}$ interaction at the physical point https://arxiv.org/abs/2603.01566 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01566v1 Announce Type: new Abstract: We report the S-wave interactions between the nucleon ($N$) and the triply charmed Omega baryon ($\Omega_{\mathrm{ccc}}$) using (2+1)-flavor lattice QCD with a physical pion mass ($m_\pi \simeq 137.1$ MeV) on a lattice volume $\simeq (8.1~\mathrm{fm})^3$. The charm quark is implemented with a relativistic heavy-quark action at its physical mass. Employing the time-dependent HAL QCD method, the $N-\Omega_{\mathrm{ccc}}$ potentials in the spin-1 ($^3\mathrm{S}_1$) and spin-2 ($^5\mathrm{S}_2$) channels are extracted. In both channels, overall attraction is found with the scattering parameters, $a_0 = 0.56(0.13)\left(^{+0.26}_{-0.03}\right)$ fm and $r_{\mathrm{eff}} = 1.60(0.05)\left(^{+0.04}_{-0.12}\right)$ fm for the $^3\mathrm{S}_1$ channel, and $a_0 = 0.38(0.12)\left(^{+0.25}_{-0.00}\right)$ fm and $r_{\mathrm{eff}} = 2.04(0.10)\left(^{+0.03}_{-0.22}\right)$ fm for the $^5\mathrm{S}_2$ channel, indicating the absence of a dibaryon bound state. The extracted potentials are further decomposed into spin-independent and spin-dependent components, which provides a useful handle to investigate the underlying interaction mechanism. The spin-independent potential is a dominant component and features a short-range attractive core and a long-range attractive tail, while the spin-dependent potential shows short-range attraction (repulsion) in the spin-1 (spin-2) channel. Qualitative comparisons with previous studies of the $N$-$J/\psi$ and $N-\Omega_{\rm{sss}}$ systems at $m_\pi \simeq 146$ MeV are provided, emphasizing the role of heavy-hadron chromo-polarizability arising from soft-gluon exchange between the nucleon and flavor-singlet hadrons. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) From strong interactions to Dark Matter: the non-perturbative QCD sphaleron rate https://arxiv.org/abs/2603.01577 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01577v1 Announce Type: new Abstract: Acceptance plenary talk for the 2025 Kenneth G.~Wilson Award for Excellence in Lattice Field Theory: For significant contributions to the understanding of topology in QCD, QCD-like, and large-$N_c$ gauge theories, including algorithmic developments to reduce topological freezing, studies of Dirac spectral properties, and axion phenomenology. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Meson spectrum and low-energy constants in large-$N$ QCD https://arxiv.org/abs/2603.01583 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01583v1 Announce Type: new Abstract: We present new non-perturbative results about the meson spectrum and the low-energy constants of QCD in the 't Hooft large-$N$ limit, $N\to\infty$ with $N_{\scriptscriptstyle{\rm f}}/N\to 0$. These are obtained from lattice Monte Carlo simulations of the Twisted Eguchi-Kawai (TEK) model up to $N=841$. More precisely, we will discuss: our findings for the meson mass spectrum; the determination of the radial Regge trajectories in the $\pi$ and $\rho$ channels; the computation of the coefficients of the $1/N$ expansion of the chiral condensate, of the pion decay constant, and of the next-to-leading-order coupling $\bar{\ell}_4$, up to $\mathcal{O}(1/N^3)$ from the combination of TEK and standard finite-$N$ results. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Spatially inhomogeneous confinement-deconfinement phase transition in accelerated gluodynamics https://arxiv.org/abs/2603.01754 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01754v1 Announce Type: new Abstract: This study explores confinement-deconfinement transition properties of SU($3$) Yang--Mills theory under weak accelerations at finite temperatures, using first-principles lattice simulations. The system is formulated in the Rindler spacetime, and the properties are studied from the perspective of a co-accelerating observer situated at the center of the lattice. We found that spatially separated confinement and deconfinement phases can coexist in the Rindler spacetime within certain intervals of temperature and acceleration. The position of the boundary between the phases is calculated as a function of temperature for several accelerations, and it is in accordance with the TE prediction, although a small deviation is observed. Moreover, in the weak acceleration regime, the critical temperature of the system is found to coincide with that of non-accelerated gluodynamics. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Accurate B meson and Bottomonium masses and decay constants from the tadpole improved clover ensembles https://arxiv.org/abs/2603.01846 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01846v1 Announce Type: new Abstract: We present a determination of the bottom quark mass, the masses of S-wave bottom mesons, and their decay constants using an anisotropic clover fermion discretization for the heavy quark, on $2+1$ flavor isotropic QCD ensembles. Our analysis is based on 16 ensembles spanning 6 lattice spacings, with pion masses in the range of 135-350 MeV and several values of the strange quark mass. We demonstrate that the effective anisotropy parameter for the heavy quark approaches unity with controllable $\mathcal{O}(a^2)$ corrections. A non-perturbative renormalization procedure is developed and validated through predictions of the bottom quark mass and decay constants. This framework enables calculations at the physical $b$-quark mass even on lattices with spacing $a \sim 0.1$ fm, where $m_b a \sim 2.5$, while keeping discretization errors in hadronic matrix elements at the $\sim 10$% level which can be eliminated properly through the continuum extrapolation. Using the physical $\Upsilon$ mass as input, we obtain $m_b^{\overline{\mathrm{MS}}}(m_b) = 4.185(37)$ GeV and the full spectrum of S-wave bottom mesons with 0.1% uncertainty or less. Pseudoscalar and vector decay constants and their ratios for all kinds of S-wave bottom mesons are also provided. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Using lattice chiral effective theory to study pi-pi scattering https://arxiv.org/abs/2510.15187 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2510.15187v3 Announce Type: replace Abstract: We use lattice field theory to study the finite-volume energy spectrum of the $\pi\pi$ system in $SU(2)$ chiral effective field theory (ChEFT) at leading order in the chiral expansion. \hl{This finite-volume spectrum can be directly related to the (infinite-volume) $\pi\pi$ scattering phase shifts by L\"uscher's formula.} We compare our results to the finite-volume spectrum obtained from lattice QCD \hl{by the RBC-UKQCD collaboration}. Our calculation and the lattice QCD calculation are both performed with the physical pion mass and the same \sout{physical volume}\hl{lattice volume (as measured in physical units)}. However, we find significant differences between the two calculations in the isospin $I=0$ channel. In particular, there is a nearly stable $\sigma$ resonance in our lattice ChEFT calculation, which is absent in the lattice QCD calculation. This likely indicates that ChEFT does not converge well with a naive lattice regularization. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) One-quark state near a boundary of the confinement phase of QCD https://arxiv.org/abs/2510.24363 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2510.24363v2 Announce Type: replace Abstract: We discuss a one-quark state in the confinement phase near a reflective chromometallic boundary both at finite and zero temperature. Using numerical simulations of lattice Yang-Mills theory, we show that the test quark is confined to the neutral mirror by an attractive potential of the Cornell type, suggesting the existence of a mirror-bound one-quark state, a "quarkiton." Surprisingly, the tension of the string spanned between the quark and the mirror is lower than the fundamental string tension. The quarkiton state exhibits a partial confinement: while the quark is localized in the vicinity of the mirror, it can still travel freely along it. Such quarkiton states share similarity with the surface excitons in metals and semiconductors that are bound to their negatively charged images at a boundary. The quarkitons can exist at the hadronic side of the phase interfaces in QCD that arise, for example, in the thermodynamic equilibrium of vortical quark-gluon plasma. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Position-space sampling for local multiquark operators in lattice QCD using distillation and the importance of tetraquark operators for $T_{cc}(3875)^+$ https://arxiv.org/abs/2510.26459 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2510.26459v2 Announce Type: replace Abstract: Obtaining hadronic two-point functions is a central step in spectroscopy calculations in lattice QCD. This requires solving the Dirac equation repeatedly, which is computationally demanding. The distillation method addresses this difficulty by using the lowest eigenvectors of the spatial Laplacian to construct a subspace in which the Dirac operator can be fully inverted. This approach is efficient for nonlocal operators such as meson-meson and baryon-baryon operators. However, local multiquark operators with four or more (anti)quarks are computationally expensive in this framework: the cost of contractions scales with a high power of the number of Laplacian eigenvectors. We present a position-space sampling method within distillation that reduces this cost scaling by performing the momentum projection only over sparse grids rather than the full spatial lattice. We demonstrate the efficiency of this unbiased estimator for single-meson, single-baryon and local tetraquark operators. Using Wilson-clover fermions at the $SU(3)$-flavor-symmetric point, we apply this method to study the importance of local tetraquark operators for extracting the finite-volume $T_{cc}(3875)^+$ spectrum. To this end, we extend a large basis of bilocal $DD^*$ and $D^*D^*$ scattering operators by including local tetraquark operators. The inclusion of local operators leads to significant shifts in the estimates of several energy levels. Finally, we show the effect of these shifts on the $DD^*$ scattering phase shift from a single-channel $s$-wave L\"uscher analysis. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Precision determination of nucleon iso-vector scalar and tensor charges at the physical point https://arxiv.org/abs/2511.02326 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2511.02326v3 Announce Type: replace Abstract: We report a high precision calculation of the isospin vector charge $g_{S,T}$ of the nucleon using recently proposed ``blending" method which provides a high-precision stochastic estimate of the all-to-all fermion propagator. Through multiplying the current operator by the traditional nucleon interpolator, we create a new operator that captures the major excited state contaminations. The linear combination of this new operator and traditional nucleon interpolator reduces these excited states and improves the robustness of the multi-state fit. Using 15 $N_f=2+1$ lattice ensembles which cover 5 lattice spacing, 5 combinations with the same quark masses and lattice spacing but multiple volumes, including three at the physical pion mass, we report so far most precise lattice QCD prediction $g_T^{\rm QCD} = 1.0264[77]_{\rm tot}(53)_{\rm stat} (13)_{a} (46)_{\rm FV} (01)_\chi (28)_{\rm ex} (04)_{\rm re}$ and $g_S^{\rm QCD} = 1.106[43]_{\rm tot}(31)_{\rm stat} (03)_{a} (28)_{\rm FV} (01)_\chi (08)_{\rm ex} (08)_{\rm re}$ at $\overline{\mathrm{MS}}$ 2~GeV, with the systematic uncertainties from continuum, infinite volume, chiral extrapolations, excited state contamination and also renormalization. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Non-perturbative False Vacuum Decay Using Lattice Monte Carlo in Imaginary Time https://arxiv.org/abs/2512.00542 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2512.00542v2 Announce Type: replace Abstract: We present a new method for calculating quantum tunneling rates using lattice Monte Carlo simulations in imaginary time. This method is designed with the goal of studying false vacuum decay non-perturbatively on the lattice. We derive a new formula, which is similar in form to Fermi's Golden Rule, which gives the decay rate in terms of an implicit decay amplitude. We then show how to calculate this implicit decay amplitude on the lattice. To deal with the suppression of the false vacuum state in the Euclidean path integral, we develop a new sampling method which combines results from multiple Monte Carlo simulations. For a simple family of one-dimensional quantum systems, we reproduce the tunneling rates calculated from the Schrodinger equation. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Fermion Doubling in Dirac Quantum Walks https://arxiv.org/abs/2601.15885 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2601.15885v2 Announce Type: replace-cross Abstract: We consider discrete spacetime models known as quantum walks, which can be used to simulate Dirac particles. In particular we look at fermion doubling in these models, in which high momentum states yield additional low energy solutions which behave like Dirac particles. The presence of doublers carries over to the `second quantised' version of the walks represented by quantum cellular automata, which may lead to spurious solutions when introducing interactions. Moreover, we also consider pseudo-doublers, which have high energy but behave like low energy Dirac particles, and cause potential problems regarding the stability of the vacuum. To address these issues, we propose a family of quantum walks, that are free of these doublers and pseudo-doublers, but still simulate the Dirac equation in the continuum limit. However, there remain a small number of additional low energy solutions which do not directly correspond to Dirac particles. While the conventional Dirac walk always has a zero probability for the walker staying at the same point, we obtain the family of walks by allowing this probability to be non-zero. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) An EFT approach to Color decoherence in jet quenching https://arxiv.org/abs/2603.00238 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00238v1 Announce Type: new Abstract: We use the EFT developed in \cite{Mehtar-Tani:2025xxd}, to understand the interference driven phenomenon of color decoherence in inclusive jet production in a dense nuclear medium such as Nuclei or Quark Gluon Plasma. Using the factorization formula in \cite{Mehtar-Tani:2024smp,Mehtar-Tani:2025xxd}, expressed as a series of multi-sub-jet operators, we define and calculate the contribution of the two sub-jet effective operator. This explicitly reveals the emergent angular scale $\theta_c$ that controls color decoherence as well an intricate renormalization group structure for the factorized functions. We show that for a jet of radius R in a medium of size L characterized by a jet quenching parameter $\hat q$, both the LPM effect and color decoherence are controlled by a single dimensionless parameter $\sqrt{\hat q L}LR$ and therefore are equally important for phenomenology. This paper shows how interference driven emergent effects can be included in a factorized framework for computing jet observables in heavy ion collisions. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Machine Learning insights on the Z3 3HDM with Dark Matter https://arxiv.org/abs/2603.00254 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00254v1 Announce Type: new Abstract: We study a 3-Higgs Doublet Model (3HDM) with an imposed Z3 symmetry, allowing for two Inert scalar doublets and one active Higgs doublet. The WIMP dark matter candidates correspond to two mass-degenerate states, H1 and A1, which possess opposite CP quantum numbers and can reproduce the correct relic density simultaneously with all theoretical and experimental constraints. We use state-of-the-art machine learning algorithms to probe the parameter space of the model by employing an Evolutionary Strategy augmented with Novelty Reward. We consider two situations: a limit for the dark matter mixing angle {\theta} that closes a gauge annihilation channel that would deplete the DM relic density, and the general case without imposing this limit. For both scenarios, we find viable dark matter candidates within two separate mass regimes, ranging from 50 GeV < mDM < mW and 380 < mDM < 1000 GeV. Moreover, we find it is possible to fulfill all the existing constraints while still obtaining values for the dark matter-higgs coupling of order O(0.1). Exploring the model outside the {\theta} = {\pi}/4 limit proved to be an extremely challenging task, as there are regions which seem easy to explore when projected on a 2D plane, yet may be completely disconnected on the hypersurface supporting the valid points, given its non-convex and multi-dimensional nature. We consider new methods of prototype selection to seed new exploration runs, which allow for efficient global scans over the parameter space. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) A Unified Interpretation of Supernova, GRB, and QSO Time Dilation Signals in a Generalized Cosmological Time Framework https://arxiv.org/abs/2603.00427 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00427v1 Announce Type: new Abstract: Cosmological time dilation (CTD) serves as a fundamental probe of cosmic expansion, historically verified through the characteristic (1+z) broadening of Type Ia supernova (SNe Ia) light curves. However, significant tensions arise when extending this test to other astrophysical regimes. While discrete, event-based transients such as Gamma-Ray Bursts (GRBs) exhibit large scatter in interred time-dilation signatures, analyses of stochastic variability in persistent sources, specifically Quasars (QSOs), frequently yield null results. I demonstrate that these discrepancies stem from a previously overlooked distinction between discrete geometric clocks and continuous thermal emission, presenting a resolution within the framework of Generalized Cosmological Time (GCT). The central premise relies on strictly distinguishing global coordinate time, characterized by a generalized lapse function, from the local proper time measured within gravitationally bound systems. We propose that the progenitors of transients, specifically SNe Ia and GRB central engines, are effectively shielded from background time evolution due to strong gravitational binding and environmental decoupling. Consequently, they act as standard clocks tracing pure geometric path dilation, obeying \tau_{\rm obs} \propto (1+z)^{1+b/4}. Conversely, the lack of dilation in QSOs is derived as a consequence of observing persistent thermal accretion disks at fixed wavelengths, introducing an intrinsic selection effect (\tau_{\rm intr} \propto (1+z)^{-2}) that masks the cosmological signal. This framework reconciles the diverse behaviors of transient and persistent sources without modifying local physical laws. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Impact of flavor changing processes on prospects for majoron discovery at intensity-frontier searches https://arxiv.org/abs/2603.00635 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00635v1 Announce Type: new Abstract: The singlet majoron $J$ is the pseudo-Nambu-Goldstone boson of a global, anomaly-free $U(1)_{B-L}$ symmetry whose spontaneous breaking generates Majorana masses for right-handed neutrinos. At tree level, the only direct coupling of $J$ to Standard Model fields is $J\nu\nu\propto m_\nu/f$ (where $m_\nu$ denotes the light neutrino mass and $f$ the $B-L$ breaking scale). Couplings to charged fermions and gauge bosons, in contrast, arise only at loop level. Consequently, $J$ can be long-lived over wide regions of parameter space, motivating displaced-decay searches. We study majoron production and displaced decays at proton beam dump experiments, neutrino facilities, and LHC forward detectors (including DUNE, NA62, FASER/FASER2, MATHUSLA, and SHiP), and we quantify the resulting reach in the $(m_J,\,f)$ plane. We show that, for realistic seesaw-induced coupling textures, lepton-flavor-violating (LFV) $\tau$ decays $\tau\to \ell J$ ($\ell=e,\mu$) dominate majoron production at these facilities and can extend sensitivity into the intermediate-mass window $m_J\simeq 0.2\text{-}1.7~\mathrm{GeV}$, complementary to supernova bounds at lower masses and to dedicated LFV searches at higher masses. We also identify physically consistent benchmark textures for the matrix $K=M_D M_D^\dagger/(vf)$ with $M_D$ denoting the Dirac mass matrix and $v$ the electroweak scale (including positive semidefinite ``anarchical'', single-flavor, and CP-violating cases) and map their impact on experimental reach. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Constraining Neutrino--Nucleon Form Factors with Charged-Current Scattering at the Electron-Ion Collider https://arxiv.org/abs/2603.00703 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00703v1 Announce Type: new Abstract: Next-generation neutrino oscillation experiments such as DUNE require percent-level knowledge of neutrino--nucleon interaction cross sections. The nucleon axial form factor $F_A(Q^2)$, parameterized by the axial mass $\MA$, is the dominant source of uncertainty in the quasi-elastic channel, and the parity-violating structure function $xF_3$ is poorly constrained on free nucleons. We propose using charged-current (CC) electron--proton scattering at the Electron-Ion Collider (EIC) to address both problems simultaneously. The measurement exploits three key features of the EIC: (1)~helicity-selective electron bunches provide \emph{in situ} electromagnetic background rejection; (2)~a longitudinally polarized proton target enables extraction of $F_A(Q^2)$ through the target-spin asymmetry $A_{UL}$; and (3)~the $y$-distribution leverage in CC deep inelastic scattering separates $F_2$ and $xF_3$ on a \emph{free proton}, without nuclear corrections. Using a Fisher-information analysis at $\sqrt{s} = 141\GeV$ with $500\fb^{-1}$ of integrated luminosity, we project the Cram\'{e}r--Rao statistical floor of $\delta\MA \approx 0.03\GeV$ (3\%). Incorporating first-order realistic detector effects: ZDC acceptance, $Q^2$ smearing (5\%), and background noise from helicity subtraction, the projected sensitivity is severely background-limited due to the small signal-to-background ratio ($S/B \approx 3 \times 10^{-4}$) in the elastic channel. Achieving competitive sensitivity ($\delta\MA \approx 0.14\GeV$) would require $\sim\!10^{-7}$ background suppression, three orders of magnitude beyond current projections. The CC DIS $y$-distribution provides sub-percent extraction of $xF_3^{\Wminus}$ over $0.05 < x < 0.5$, representing the most robust electroweak measurement in the near term. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Getting a handle on correlation functions https://arxiv.org/abs/2603.00804 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00804v1 Announce Type: new Abstract: The central objects in a quantum field theory are its n-point correlation functions and matrix elements. Their structure is determined by Lorentz invariance and leads to tensor decompositions whose Lorentz-invariant coefficient functions encode the physics of the process. For growing n, the complexity of these objects may increase considerably and make it challenging to deal with them. Here we give a pedagogical introduction to the topic and provide some tools to manage this complexity, and we will show how symmetries can be used as organizing principles. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Quark Mixing from a Lattice Flavon Model: A Four-Magnitude Parameterization https://arxiv.org/abs/2603.00810 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00810v1 Announce Type: new Abstract: We present the quark weak-mixing component of a Froggatt--Nielsen program, with one flavon and three messengers, in which a single hierarchy parameter $B$ (with $\epsilon\equiv 1/B$) and a rational-exponent ``$B$-lattice'' organize fermion Yukawa textures. Building on companion mass-fit work, we translate the lattice into sharp predictions for quark mixing. The four-magnitude parameterization serves as a practical interface between the flavon Yukawa textures and quark weak mixing observables, yielding coefficient-free ratio tests of the lattice structure. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Non-Minimal Dilaton Inflation from the Effective Gluodynamics https://arxiv.org/abs/2603.00818 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00818v1 Announce Type: new Abstract: We study single-field inflation in which the inflaton is identified with the lightest scalar (dilaton) excitation of a confining gauge theory. The inflaton potential is not postulated: it follows from the pure effective Gluodynamics Lagrangian tightly constrained by the trace anomaly and the associated infinite tower of Ward identities, yielding a Coleman--Weinberg form with a logarithmic term fixed by nonperturbative condensates. After coupling to gravity via a non-minimal interaction $\xi\,\varphi^2 R$, the Einstein-frame potential develops a plateau consistent with current CMB observables. In the large-$\xi$ limit the model approaches the standard plateau attractor, while the Migdal--Shifman(MS) logarithmic structure induces a controlled, testable deformation governed by $A/\lambda$ across the CMB window. We quantify the resulting shifts in $(n_s,r)$ and the running analytically and confirm them with numerical scans over $(\xi,\lambda,A,\mu)$, making the departure from the attractor both microphysically motivated and observationally predictive. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Covariant diffusion tensor for jet momentum broadening out of equilibrium https://arxiv.org/abs/2603.00844 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00844v1 Announce Type: new Abstract: Jets are produced in the earliest stages of heavy-ion collisions, where they can interact with a medium that is not yet close to local equilibrium. Motivated by this, we generalize the usual jet transport coefficient $\hat q$ to a Lorentz-covariant diffusion tensor $\hat q^{\mu\nu}$ within a leading-order elastic (Boltzmann/Fokker--Planck) description of jet--medium interactions. The tensor formulation organizes medium effects in a frame-covariant way and reveals additional information beyond the standard scalar definition, including energy diffusion and off-diagonal components that encode correlations between energy and momentum exchange which are absent (or redundant) in equilibrium. We illustrate the formalism in (tree-level) massless $\lambda\varphi^4$ theory for isotropic but out-of-equilibrium states. For sufficiently large jet momentum, quantum statistical effects become subleading, so that the non-equilibrium evolution can be studied reliably in the classical (Boltzmann) limit. This allows us to solve the corresponding Boltzmann equation for the medium and determine the time dependence of $\hat q^{\mu\nu}$ as the system approaches equilibrium. We find that out-of-equilibrium corrections can either enhance or reduce jet momentum broadening, depending on the initial distribution function. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Comments on "Unified neutrino mixing and approximate $\mu-\tau$ reflection symmetry" (Modern Physics Letters A 40 (2025) 26, 2550097 [arXiv:2502.18029 [hep-ph]]) https://arxiv.org/abs/2603.00885 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00885v1 Announce Type: new Abstract: Resolving mass ordering is the important thing in the neutrino physics. In Ref.\cite{yt} the authors investigate the phenomenology of a unified neutrino mixing framework and reveal that the predicted sum of neutrino masses derived from an approximate $\mu-\tau$ reflection symmetric flavor neutrino mass matrix based on the unified neutrino mixing with an inverted mass ordering, is excluded from DESI2024 and Supernova Ia luminosity distance data. We note that in Ref.\cite{yt} an error is present in Eq.(20), {\it i.e.}, the expression for $ M_{23}^{\mu-\tau} $, a similar error also appears in Eq.(26) for $M_{13}^{\mu-\tau}$. That is, the condition that $M_{ee}$ and $M_{\mu\tau}$ are real is not added. We add the condition and analyze its consequences. Using the newest data\cite{azz}, it is obtained that the predicted sm derived from the approximate $\mu-\tau$ reflection symmetric neutrino mass matrices $M_{23}$ for both NO and IO are allowed. We note also that their conclusion is invalid, as it is based on outdated data. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Anisotropic flows of light-flavor and charmed hadrons in Pb+Pb collisions at LHC energy https://arxiv.org/abs/2603.00915 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00915v1 Announce Type: new Abstract: We apply a constituent quark equal-velocity combination (EVC) model to study the elliptic flow ($v_{2}$) and triangular flow ($v_{3}$) of light-flavor and single-charmed hadrons in Pb+Pb collisions at $\sqrt{s_{NN}}=$ 2.76 and 5.02 TeV. $v_{2,3}$ of hadrons in the EVC model can be expressed as a linear superposition of the $v_{2,3}$ of quarks at the same velocity as that of the hadrons. We find that available experimental data for $v_{2}$ and $v_{3}$ of $p$, $\Lambda$, $\Xi$, and $\Omega$ as the function of transverse momentum ($p_{T}$) can be consistently explained by the EVC formula using a $v_{2}$ of up/down quarks and a $v_{2}$ of strange quarks. In comparison with $v_{2}$ data of $\phi$ at $\sqrt{s_{NN}}=$2.76 TeV which can be naturally explained by $v_{2}$ of strange quarks, explanation of data of $\phi$ mesons at $\sqrt{s_{NN}}=$5.02 TeV requires an additional contribution of two-kaon coalescence, which indicates approximately 20% influence of final-state hadronic rescattering on $v_{2}$ of $\phi$ at $\sqrt{s_{NN}}=$5.02 TeV. Using $v_{2}$ and $v_{3}$ of light-flavor quarks obtained in studying light-flavor hadrons and $v_{2}$ and $v_{3}$ of charm quarks determined from $D^{0}$ meson data, we apply the EVC model to predict the anisotropic flows of $D_{s}^{+}$, $\Lambda_{c}^{+}$, $\Xi_{c}^{0}$, and $\Omega_{c}^{0}$ and compare them with the available experimental data. The preliminary data for $v_{2}$ of $D^{0}$, $D_{s}^{+}$, and $\Lambda_{c}^{+}$ at $\sqrt{s_{NN}}=$ 5.36 TeV are found to be naturally described by the EVC model. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Probing non-unitarity of the PMNS matrix in P2SO and comparison with DUNE https://arxiv.org/abs/2603.01031 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01031v1 Announce Type: new Abstract: We compare the sensitivity of the upcoming long-baseline neutrino experiments Protvino to Super-ORCA (P2SO) and the Deep Underground Neutrino Experiment (DUNE) to non-unitarity (NU) of the leptonic mixing matrix in a model-independent framework. NU can arise in theories beyond the Standard Model that include heavy neutral leptons. These effects can modify neutrino oscillation probabilities and introduce new sources of CP violation, which may affect precision measurements of neutrino parameters. We find that DUNE provides stronger bounds on $\alpha_{11}$ and $|\alpha_{21}|$, while P2SO shows better sensitivity to $\alpha_{22}$ and $\alpha_{33}$, mainly due to its longer baseline and stronger matter effects. Our results show that DUNE (P2SO) will be able to improve the current bounds of $\alpha_{11}$ ($\alpha_{33}$). We further examine correlations with standard oscillation parameters and quantify the impact of NU on mass hierarchy, octant, and CP-violation sensitivities. Our results show that these sensitivities depend upon NU in a non-trivial way interconnecting the parameter degeneracies and matter effects. Our results demonstrate the complementarity of P2SO and DUNE in probing NU and show that NU can significantly influence next-generation precision oscillation studies. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Quark-diquark effective mass formalism for heavy baryon spectroscopy https://arxiv.org/abs/2603.01037 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01037v1 Announce Type: new Abstract: We present a comprehensive study of heavy flavor baryons within a quark-diquark effective mass formalism, formulated using the effective masses of quarks and diquarks inside baryons. We predict the masses of $J^P=\frac{1}{2}^+$ and $J^P=\frac{3}{2}^+$ states under two complementary scenarios: the quark-quark interaction picture (Scenario I) and the quark-diquark interaction picture (Scenario II). Scenario I considers all possible quark-quark correlations, while Scenario II employs fixed spin-flavor diquark configurations, treating the baryon as an effective quark-diquark system. Using current experimental data, we estimate constituent quark masses, diquark masses, and hyperfine interactions, and include a mass-dependent binding energy term to account for short-range chromoelectric effects. The analysis shows that the binding energy plays a crucial role in describing heavy-heavy diquarks. The predicted baryon masses show excellent agreement with experimental and lattice QCD results across the charm and bottom sectors. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Multi-channel phase space with Feynman-diagram-gauge amplitudes https://arxiv.org/abs/2603.01139 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01139v1 Announce Type: new Abstract: Multi-channel phase space with a single Feynman diagram enhancement is a powerful tool for high-energy physics event generation if a diagram with a singular propagator dominates the total scattering amplitude at the corresponding singular kinematical region, and when the interference among amplitudes is not larger than the square of each amplitude. These conditions are satisfied in the Feynman-diagram-gauge amplitudes for both unbroken (QED and QCD) and broken (EW) gauge theories. We illustrate the usefulness of this method in lepton collider processes that are challenging to accurately simulate at very high energies, i.e., $ l\bar{l} \to \nu_l \bar{\nu}_l t\bar{t} H $, $ l \bar{\nu}_l t\bar{b} H $, and $ l \bar{l} t\bar{t} H $, in the SMEFT with a complex top-Yukawa coupling. The total cross sections of the latter two processes contain lepton-mass singularities arising from $t$-channel photon-exchange diagrams. To address this issue, we develop a phase-space parametrization that accurately generates the distributions of forward-emitted charged leptons. We modify the \HELAS\ library to evaluate helicity amplitudes in the singular region so that vertices at very small invariant momentum square of order $m_e^2$ can be accurately evaluated even at multi-TeV energies. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Elastic Hadron Scattering at High Energies https://arxiv.org/abs/2603.01277 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01277v1 Announce Type: new Abstract: A brief historical overview of various modern approaches to the problem under consideration is given. It includes existing models based on a sum of different terms of the scattering amplitude with different signs and Regge-eikonal models based on the Born terms of the scattering amplitudes. An example of such a model is a new Regge-eikonal model is given, taking into account the generalized structure of nucleons (the HEGS model), which is based on the analyticity of the scattering amplitude. A unified quantitative description of various hadron reactions and a description of differential cross sections and the spin-correlation parameter for interactions were obtained. In the framework of the model, the existence of experimental data of elastic hadron scattering in the energy range of LHC and in a wide energy region $\sqrt{s}=3.6 -13000$ GeV was describe a quantitatively from a unified point of view. The predictions for $\sigma_{tot}(s)$ at superhigh energies are presented. The possible thin structure of differential cross sections at small angles of elastic nucleon-nucleon scattering at high energies is discussed. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) LHEReader: Simplified Conversion from Les Houches Event Files to ROOT Format https://arxiv.org/abs/2603.01489 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01489v1 Announce Type: new Abstract: We present the \textsc{LHEReader} program that converts an Les Houches Event file into a \Root file allowing one to subsequently analyze the file using \Root. We evaluate the performance of this conversion by simulating $pp\to jj$ and $e^+e^- \to ZH$. The application of this program is illustrated through the simulation of $pp\rightarrow ZH$, with the $Z\to\ell^+\ell^-$ and $H\to b\bar{b}$, analyzing the events at the parton level after hard-scatter event generation as well as after the stage of fast simulation using \MadAnalysis. The analysis is implemented in \Root demonstrating the use of this program. The program is available here: https://github.com/amanmdesai/LHEReader High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Threshold Cusp Structures in the Presence of Isospin Symmetry Breaking https://arxiv.org/abs/2603.01518 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01518v1 Announce Type: new Abstract: We study the behavior of the cusp structures focusing on the isospin-breaking effects. The properties of the near-threshold exotic hadrons are encoded in the shapes of the cusp structures. In hadron scattering, it is often the case that the thresholds of isospin partner channels are located within a narrow energy region. To analyze the scattering in such systems, it is therefore essential to study the cusp structures that emerge at two closely separated thresholds with isospin symmetry breaking. In this study, we propose a practical representation of the scattering amplitude and show that the two neighboring cusp structures are related through the isospin symmetry. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Covariant Cherenkov Radiation and its Friction Force https://arxiv.org/abs/2603.01636 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01636v1 Announce Type: new Abstract: We derive the covariant generalization of the Frank-Tamm formula describing the Cherenkov radiation by a charged particle moving uniformly with a speed faster than the local speed of light within a homogeneous dielectric medium. We use our result to derive the covariant Cherenkov radiation reaction force and obtain a four-force explicitly orthogonal to particle four-velocity consistent with a relativistic friction force. We present the photon emission spectrum that is dependent primarily on the dielectric properties of the medium. We hint at a possible use of this work to interpret an excess of soft photons seen in relativistic hadron collisions. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Schwinger--Keldysh formulation of electromagnetic leptogenesis in an EFT framework https://arxiv.org/abs/2603.01652 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01652v1 Announce Type: new Abstract: We study TeV-scale electromagnetic leptogenesis (EMLG) in an effective field theory (EFT) framework, starting from an ultraviolet (UV)-complete model in which integrating out heavy states generates the gauge-invariant dimension-six dipole operators $O_{NB}$ and $O_{NW}$. After electroweak symmetry breaking these operators induce effective dipole couplings of the right-handed neutrinos $N$ to $\gamma$, $Z$, and $W^{\pm}$, enabling decays, inverse decays, and scattering processes in the electroweak crossover window. Gauge invariance enforces a Higgs insertion and thus a parametric suppression of both the CP-odd source and the washout in the non-resonant, hierarchical regime, preventing reproduction of the observed baryon asymmetry. We therefore focus on the quasi-degenerate limit, in which the self-energy contribution to the CP asymmetry is resonantly enhanced and coherent flavor dynamics among the nearly degenerate $N$ becomes essential. Using the CTP/Schwinger--Keldysh formalism, we derive density-matrix quantum kinetic equations (QKEs) whose collision term, at leading order in the effective dipole couplings and SM gauge interactions, incorporates $1\leftrightarrow 2$ processes and the leading $\Delta L=0$ scatterings in a unified and non-overcounted manner, without the need for real-intermediate-state (RIS) subtraction. Solving the resulting system numerically, we present a coherent EFT pipeline from UV matching and renormalization-group (RG) running to electroweak-scale effective dipole couplings, resonantly regulated CP sources, and the frozen-out baryon asymmetry. For both thermal and zero initial heavy-neutrino abundances, we find in the oscillation-motivated region that the undiluted freeze-out yield $Y_B^{\rm FO}$ can exceed $Y_B^{\rm obs}\simeq 8.7\times10^{-11}$ by several orders of magnitude. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) Flux Estimates and Detection Prospects for Lunar Geoneutrinos https://arxiv.org/abs/2603.01678 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01678v1 Announce Type: new Abstract: The distribution of heat-producing elements (U, Th, K) within the Moon is critical for understanding its thermal evolution and formation history. Based on a refined lunar interior model, we calculate the geoneutrino fluxes at two representative detector locations that bracket the expected signal intensity. The maximum flux is found to be slightly lower than the corresponding predicted fluxes for the KamLAND site on Earth, while the minimum flux is approximately a factor of 8.63 lower than this maximum value. The angular distributions of geoneutrinos arriving at the two locations were further computed. Finally, we evaluate the detection prospects for lunar geoneutrinos using three reaction channels: inverse beta decay reaction, elastic scattering on electrons, and a novel radiochemical approach based on $\bar{\nu}_e + ^3$He $\to e^+ + ^3$H. For each reaction, we calculate the expected event rates and briefly discuss the potential for measuring the total geoneutrino flux, as well as the relative contributions from U, Th, and K. High_Energy_Physics/hep-ph_(High_Energy_Physics_-_Phenomenology) What IIB looks IIA string: String Cobordisms via Non-Compact CFTs https://arxiv.org/abs/2603.00225 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00225v1 Announce Type: new Abstract: The Swampland Cobordism Conjecture predicts the existence of end-of-the-world branes for every consistent Quantum Gravity theory, and domain walls connecting the Landscape. A perturbative string worldsheet description of these objects is only expected to exist when certain worldsheet invariants are vanishing or coincide across the domain wall. In this paper, we observe that many of these worldsheet obstructions can be evaded by allowing non-compact string worldsheets as part of the bordism. Using these ideas, we provide a worldsheet QFT (flowing to a critical CFT under RG flow) that connects the worldsheets of 0A and 0B string theory, as well as those of IIA and IIB string theories. The non-compact character of these interpolations means that the description of the actual domain walls develop strongly coupled regions described by a linear dilaton background, where the worldsheet description breaks down. As a result, the IIA/IIB domain wall requires a strongly coupled region, in agreement with effective field theory considerations. Our constructions are heavily inspired by supercritical string theory, but are logically independent from it. We also analyze the fate of IIA/IIB NS5 branes as they cross the domain wall between these two theories. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Universal relation between $C_{T}$ and the CFT Weyl anomaly https://arxiv.org/abs/2603.00321 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00321v1 Announce Type: new Abstract: We establish a universal relation between the coefficient $C_T$ of the energy momentum tensor two point function and the coefficient $c$ multiplying the term quadratic in the Weyl tensor in the Weyl anomaly of a generic even dimensional conformal field theory. Our first derivation combines long known holographic results for $C_T$ and for the Weyl anomaly in Einstein bulk gravity with a recently obtained Chern Gauss Bonnet formula for compact Einstein manifolds. This theorem isolates the Weyl squared contribution in the relation between the Euler density and the $Q$ curvature, allowing us to identify the relevant quadratic term unambiguously. We then provide a genuine CFT derivation based on the renormalization group running of the TT correlator with respect to the arbitrary but necessary mass scale $\mu$. Several known examples are revisited to illustrate and validate the general result. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Resolution of Black Hole Singularities in Jackiw-Teitelboim Gravity https://arxiv.org/abs/2603.00450 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00450v1 Announce Type: new Abstract: In Jackiw-Teitelboim gravity, the naive Schwarzian quantum mechanics leads to a continuous bulk spectrum, in apparent contradiction with the finite entropy of the black hole, which requires a discrete spectrum with level spacing of order $e^{-S_0}$. It was recently shown that restoring spectral discreteness with random statistics requires the introduction of a left confining potential that becomes relevant when the renormalized wormhole length reaches order $e^{S_0}$. In this work, we show how the known perturbative results of JT gravity are recovered within this modified framework. More importantly, we demonstrate that this modification has a direct dynamical consequence: it resolves the black-hole singularity. The confining potential generates a repulsive force at exponentially large wormhole length, preventing the indefinite growth that would otherwise lead to a singularity. We explain in detail how this turnaround arises and explore its implications for late-time bulk gravitational dynamics, the disappearance of horizons, and possible observational consequences. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Yukawa Textures with Enhanced Symmetries in Heterotic Calabi-Yau Compactifications https://arxiv.org/abs/2603.00864 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00864v1 Announce Type: new Abstract: We clarify the structure of Yukawa couplings and mass matrices for matter fields in heterotic string theory on smooth Calabi-Yau threefolds with standard embedding. The topological structure of Calabi-Yau threefolds leads to interesting Yukawa textures that cannot be derived from group-theoretical symmetries, e.g., the so-called Weinberg texture in the case of two generations of matter fields. Furthermore, we find that a $U(2)$ flavor symmetry, which plays an important role in controlling higher-dimensional operators in the Standard Model effective field theory, emerges at specific loci in the moduli space of multi-Higgs fields. Small perturbations around these loci generate semi-realistic patterns of quark masses and mixings. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Proofs of some conjectures of Okazaki and Smith on line defect half-indices of ${\rm SU}(N)$ Chern-Simons theories https://arxiv.org/abs/2603.01240 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01240v1 Announce Type: new Abstract: Okazaki and Smith discovered many elegant formulas expressing some matrix integrals as some celebrated $q$-series such as the Rogers--Ramanujan functions or Jacobi theta functions. These integrals arise as Wilson line defect half-indices of 3d $\mathcal{N}=2$ supersymmetric ${\rm SU}(N)$ Chern-Simons theories. We evaluate them by carefully calculating the constant terms of some infinite products. Along the way we use some crucial facts about antisymmetric multivariate formal Laurent series. Consequently, we prove three general conjectures of Okazaki and Smith which provide explicit formulas for half indices of the ${\rm SU}(N)_{-N-k}$ ($k=0,1/2,1$) Chern-Simons theories. During the process, we extend these ${\rm SU}(N)$ formulas to include one additional parameter. Furthermore, we generalize the ${\rm SU}(N)_{-N-1/2}$ and ${\rm SU}(N)_{-N-1}$ conjectures by calculating the corresponding half-indices of Wilson lines of arbitrary charge. As a special instance of our generalizations, we also confirm the ${\rm SU}(3)_{-4}$ conjecture of Okazaki and Smith. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) The Generalized Klein--Gordon Oscillator in Doubly Special Relativity: A Complexified Morse Interaction https://arxiv.org/abs/2603.01296 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01296v1 Announce Type: new Abstract: We investigate the one-dimensional \emph{Generalized Klein--Gordon Oscillator} (G-KGO) within Doubly Special Relativity (DSR) kinematics. The G-KGO extends the Klein--Gordon oscillator by replacing the usual linear non-minimal coupling with a general interaction function $f(x)$, leading to a factorized (SUSY-like) Schr\"odinger operator $H_-=\mathcal{A}^{\#}\mathcal{A}$ whose real spatial spectrum $\{\epsilon_n\}$ can be ensured either by Hermiticity or, for complex $f(x)$, by $\eta$-pseudo-Hermiticity and/or $\mathcal{PT}$ symmetry with a consistent metric inner product \cite{Bender1998,Bender2007RPP,BBJ2002PRL,Mostafazadeh2002,Mostafazadeh2003,Mostafazadeh2010,ElGanainy2018NatPhys}. DSR is then implemented at the level of the energy reconstruction map $\epsilon_n\mapsto E_{n,\pm}$, and we provide closed-form Magueijo--Smolin (MS) and Amelino--Camelia (AC) branches. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Higgs Branch and VOA of 4d $\mathcal{N}=2$ SCFTs from IIB https://arxiv.org/abs/2603.01742 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01742v1 Announce Type: new Abstract: We study the Higgs branch and associated vertex operator algebra (VOA) of 4d $\mathcal{N}=2$ superconformal field theories (SCFTs) from the geometric engineering of IIB superstring on canonical threefold singularities. For terminal singularities, we explain how to derive the 4d Higgs branch from their small resolution. We also investigate singularities with compact 4-cycles in their crepant resolution, and discuss different ways to compute their Higgs branch. Using a symplectic duality argument, we propose the first examples of 4d $\mathcal{N}=2$ SCFTs with the E-type Kleinian singularities as their Higgs branches, and conjecture their associated VOA to be affine E-type W-algebra. Many new VOAs with no known W-algebra descriptions are found, with conjectured associated varieties. We investigate the singularities associated with lisse VOAs and propose predictions for the BPS quivers of $D_N^N[k]$ and $E_7^{14}[k]$ from the perspective of deformed singularities. We further analyze the structure of the Schur index using the Coulomb branch IR formula, derive the expressions for the Schur index corresponding to these two classes of singularities, and illustrate, in a general setting, how the Schur index is determined by the BPS quiver. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Singularities in the RG flow https://arxiv.org/abs/2603.01900 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01900v1 Announce Type: new Abstract: In this work, we show examples when a perturbatively irrelevant operator becomes relevant in the infrared because of the presence of an IR singularity (IR Landau pole). An example of this behavior is the four-fermion interaction that allows the formation of bound states. The reason of the appearance of the IR Landau pole is not the singular loop as in the purely perturbative case, but the infinite number of modes appearing in the RG flow. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Effective potentials for de Sitter and anti de Sitter quantum fields https://arxiv.org/abs/2603.02140 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.02140v1 Announce Type: new Abstract: We derive a systematic treatment of one-loop effective potentials for interacting scalar fields in curved spacetimes, providing a general formula valid in arbitrary geometries and explicit results for de Sitter and anti-de Sitter backgrounds. We then compute the effective potential for a scalar $O(N)$ theory on a de Sitter space in any integer dimension. In $d=3$ and dimensional regularization, we extend the calculation up to two loops and compute the $\beta$-function and the anomalous mass dimension. They coincide exactly with flat-space results, despite dramatic curvature modifications to physical masses/couplings. The flat limit $R\to\infty$ recovers Coleman-Weinberg, confirming consistency. Working in $d=3$ dimensions, we repeat the calculation for $AdS_3$ by using point-splitting regularization, obtaining analogous results for the $\beta$-function and anomalous mass dimension. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Line Defects in Liouville Conformal Field Theory: Localized Cosmological Constants and Decohered Hyperbolic Geometries https://arxiv.org/abs/2603.02166 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.02166v1 Announce Type: new Abstract: The study of quantum impurities has long been a central and inspiring theme in quantum many-body physics. Localized impurities are modeled by line defects in quantum field theory. We describe a line defect in Liouville CFT realized as a ``localized cosmological constant'': a non-topological line insertion into the Liouville path integral that is tractable at both weak and strong defect coupling. At weak coupling, we analyze the defect perturbatively and characterize it through its correlations with local operators, energy and information transport, the Casimir energies associated with fusion, and corrections to the open string channel spectrum. We also study the effect of a cuspidal deformation of the defect locus on these observables and describe novel monotonicity properties as the cusp angle is varied. These results derived using perturbation theory are more generally applicable to pinning defects constructed from scalar primary operators in compact $2d$ CFTs. At strong coupling, in a semiclassical limit, the defect admits a geometric interpretation in terms of a discontinuity in the extrinsic curvature of the $1d$ defect locus embedded in $2d$ hyperbolic geometries. The observables characterizing the defect in this regime are computed by gluing hyperbolic surfaces across the defect, and are compared with the corresponding weak coupling results. The correlations across the defect, both at weak and strong coupling, can also be realized by an effective ``decohered FZZT interface'' constructed by diagonal gluing of two copies of the fixed-length FZZT boundary state. These line defects also have interesting interpretations in other models, in terms of end-of-the-world branes in Jackiw-Teitelboim gravity, dust shells in AdS$_3$ gravity, and interfaces with a proliferation of non-abelian Wilson loops in $4d$ $\mathcal{N}=2$ gauge theories. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) A Matrix Theory Construction of the IIA/IIB Wall https://arxiv.org/abs/2603.02199 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.02199v1 Announce Type: new Abstract: In this note, we give a non-perturbative construction of a lightlike domain wall separating IIA and IIB string theories in 10D in the framework of discrete light-cone quantization (DLCQ). In this setting, generalizations of the BFSS conjecture relate the 10D flat space limit to matrix string theories (MSTs) for IIA and IIB. The former is equivalent to the large-$N$ limit of 2D Super Yang-Mills theory, while the latter is the large-$N$ limit of 3D ABJM theory with $\pm 1$ Chern-Simons levels. Our construction requires the string coupling to vanish at the location of the wall, and we show that BPS IIA $D0$-branes become non-BPS IIB $D0$-branes as they cross the it, as anticipated in \cite{Heckman:2025wqd}. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Axiverse Lampposts https://arxiv.org/abs/2602.23424 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2602.23424v1 Announce Type: cross Abstract: The string axiverse predicts a unique connection between the high scales approachable only through theory and the low energies within reach of experimental verification: a multitude of light, feebly interacting axions. In order to capture the collective effects of such an axion ensemble, we model the string axiverse by $N$ coupled axions with a simple assumption: hierarchical axion masses that arise from hierarchical instantons with statistically distributed axion couplings. In this limit, we find that axion field ranges, which determine late-time cosmological abundances, shrink as $1/\sqrt{N}$ as the number of axions grows. Moreover, the heaviest modes tend to align with the smallest kinetic eigenvalues, further reducing their field ranges. Interactions with the Standard Model (SM) are largely set by the kinetic structure and do not grow with $N$, thus suppressing detection prospects relative to the individual-axion expectation. The exceptions are the ensemble's lightest and heaviest states as well as the Quantum Chromodynamics (QCD) axion, which incur no such suppression. We further find that coupled axiverse dark matter has parametrically relaxed tuning on initial conditions when produced via long, low-scale inflation relative to independent axions and high-scale inflation. Taken together, these results sharpen the observational outlook: the most accessible signals typically come from the QCD axion and from heavy axions that make up small dark matter subcomponents. An anthropic plateau of comparable energy density states produces subdominant signals; meanwhile, if light axions have SM interactions independent of QCD, they can also be within reach of future direct-detection experiments. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Gauss-Bonnet lensing of spinning massive particles in static spherically symmetric spacetimes https://arxiv.org/abs/2603.00650 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00650v1 Announce Type: cross Abstract: We extend the finite-distance Jacobi-metric Gauss-Bonnet framework of Li \textit{et al}. [10.1103/PhysRevD.101.124058] to massive test particles carrying intrinsic spin. At pole-dipole order, the Mathisson-Papapetrou-Dixon dynamics generically drives the spatial ray away from Jacobi geodesics, so the standard Gauss-Bonnet construction must be reformulated to accommodate a non-geodesic particle boundary. Working in the aligned-spin planar sector with the Tulczyjew-Dixon spin supplementary condition and retaining terms linear in the spin, we derive a spin-generalized deflection identity in which the spin dependence enters through a single additional boundary functional: the geodesic-curvature integral of the physical ray in the Jacobi manifold. We show that Li's circular-orbit boundary choice remains fully compatible with this generalization and continues to collapse the Gaussian-curvature surface term to an effective one-dimensional integral. We then provide an implementation-ready weak-field recipe that relates the required geodesic curvature directly to the MPD spin-curvature force, enabling systematic perturbative evaluation without introducing model-dependent definitions of asymptotic angles. As applications, we validate the Schwarzschild limit, including the expected linear-in-spin weak-field scaling, and compute leading spin corrections for Reissner-Nordstr\"om and Kottler (Schwarzschild-de Sitter) geometries with finite source and receiver distances. In Kottler, we show that the constant-curvature part of the cosmological constant does not generate a linear-in-spin MPD force under the Tulczyjew-Dixon condition; nevertheless, the finite-distance spin correction acquires an explicit $\Lambda$-dependence through the Jacobi-metric prefactor entering the Gauss-Bonnet boundary functional, in addition to the Weyl-driven (mass-sourced) contribution. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Casimir phenomena in bumblebee gravity https://arxiv.org/abs/2603.00850 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00850v1 Announce Type: cross Abstract: In this work, we analyze the Casimir effect associated with a massive, non-minimally coupled scalar field in static, spherically symmetric black hole spacetimes arising in bumblebee gravity. Three distinct solutions are considered, corresponding to different vacuum expectation value configurations of the Lorentz-violating vector field, including metric and \textit{metric-affine} scenarios. Finite-size effects are implemented through the Thermo Field Dynamics formalism by compactifying the radial direction, allowing the construction of renormalized vacuum expectation values of the energy-momentum tensor. Closed-form expressions for the Casimir energy and pressure are obtained in the massless limit as functions of the radial position of a spherical capacitor and the plate separation. Both observables depend explicitly on the bumblebee parameters and on the location of the apparatus relative to the horizon $R_0=2M$. In the weak-field regime, $r \gg R_0$, the standard flat-space behavior $E \propto -1/d^4$ is recovered. As $r \to R_0$, the Casimir energy vanishes while the radial pressure diverges. Inside the black hole, the interaction may alternate between attractive and repulsive regimes depending on the plate separation and on the Lorentz-violating couplings. A domain-dependent hierarchy among the three configurations emerges, with \textit{metric-affine} effects amplifying the interior vacuum energy, while configurations with simultaneous temporal and radial deformations dominate in the exterior region. Although all geometries share the same asymptotic Schwarzschild structure, their quantitative deviations become increasingly pronounced as the Lorentz-violating parameters grow. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Thermodynamic Topology and Photon Spheres Analysis of Black Holes in Brane-World: Insights from Barrow Entropy https://arxiv.org/abs/2603.00916 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00916v1 Announce Type: cross Abstract: We explore the thermodynamics and geothermodynamics of black holes with Barrow entropy in a brane-world scenario, where the horizon geometry of the black hole is regarded as a fractal structure. Our analysis reveals the behavior of heat capacity, identifying both bound and divergence points. For the Bekenstein-Hawking entropy, the divergence point exhibits smooth behavior, indicating no phase transition. In contrast, we observe divergence with Barrow entropy as the deformation parameter increases, confirming the presence of a zero point in heat capacity through various thermodynamic geometry formalisms. Additionally, we delve into thermodynamic topology, detailing the classification of black holes in the brane-world context and comparing their characteristics determined from the Bekenstein-Hawking and the Barrow entropy. Notably, fixing the deformation and cosmological parameters results in a topological charge $-1$ predominately by the dark matter parameter, which remains unaffected despite variations in other parameters. In the dS model, the cosmological horizon prevents stable photon spheres, making topological charges of $0$ and $+1$ unattainable. Incremental increases in the cosmological parameter reduce the dark matter parameter-dominated region. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Cosmological Evolution of the Universe in Torsion-based Modified Gravity https://arxiv.org/abs/2603.01043 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01043v1 Announce Type: cross Abstract: General Relativity, despite its century-long success, faces conceptual and observational challenges, including singularities, incompatibility with quantum mechanics, and the need to introduce dark matter and dark energy. Precision cosmology has also revealed persistent tensions, notably the H0 and S8 discrepancies, which question the completeness of the standard Lambda-CDM model. This thesis investigates cosmological applications of teleparallel gravity and its extensions, focusing on f(T) and f(T,T) theories. We show that torsion-based modifications can shift late-time expansion and matter clustering, alleviating the H0 and S8 tensions. Using datasets including cosmic chronometers, baryon acoustic oscillations, Type Ia supernovae, Pantheon+SH0ES, Union3, DESI, and gravitational wave standard sirens, we perform Markov Chain Monte Carlo analyses to constrain model parameters. Model-independent diagnostics using cosmography demonstrate that extended teleparallel theories can be tightly constrained. Pade approximations and direct dynamical reconstructions yield consistent results, with some models outperforming Lambda-CDM using recent DESI and Union3 data. We also propose a connection between late-time acceleration and early-Universe baryogenesis, showing that torsional gravity can reproduce the observed baryon asymmetry while remaining consistent with late-time expansion. Overall, teleparallel gravity provides a robust alternative framework capable of alleviating key cosmological tensions and linking early- and late-Universe physics. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Ultraviolet completion of the inflationary paradigm https://arxiv.org/abs/2603.01722 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01722v1 Announce Type: cross Abstract: After an exhaustive introduction highlighting the strengths and weaknesses of the non-local models proposed so far as ultraviolet completions of the Starobinsky theory, we propose a new nonlocal completion of a general $f(R)$ theory (in the Einstein's frame) suitable for driving inflation in the early universe consistently with observations. The nonlocal theory shares with $f(R)$ the same background solutions and the same equations of motion for perturbations at linear and nonlinear level. Therefore, the classical cosmological observables are not affected by the nonlocal operators needed for the quantum completion. Our construction applies to any local action written in the Einstein's frame, but we will provide the details only for two explicit examples: the Starobinsky model and a general $f(R)$ theory. The new model overcomes the incompatibility of renormalizability and stability present in the previous proposals. Since the nonlocal theory is at least super-renormalizable, but can also be finite depending on the details of the model, this work shows the consistency of the inflationary paradigm with a well-defined quantum theory of gravity at high energy. We could rephrase the latter statement saying that the success of the $f(R)$ theories in cosmology can be traced back to the existence of an ultraviolet completion that preserves all the classical features. The inflationary paradigm survives, or it is actually insensitive to quantum gravity, because it is an exact solution of quantum gravity, up to perturbative corrections. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Singular hypersurfaces and thin shells in cosmology https://arxiv.org/abs/2402.09539 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2402.09539v2 Announce Type: replace Abstract: We analyse spherically symmetric spacetimes obtained by gluing a cosmological region to a Schwarzschild black hole across a singular co-dimension one hypersurface. Assuming an arbitrary homogeneous and isotropic cosmology, and working in spacetime dimensions greater than three with general cosmological constant, we derive the stress-energy tensor required on the hypersurface directly in terms of the cosmological energy density. This general framework yields a new exact solution in four dimensions describing a radiation-filled cosmology matched to vacuum through a pressureless dust shell. A systematic exploration of parameter space reveals twenty-two distinct families of solutions, including bubble-of-cosmology and Swiss-cheese spacetimes with different global and causal structures. We also discuss possible generalisations of the construction and explain why such thin-shell cosmologies are of interest in the context of holography and quantum cosmology. For negative cosmological constant, a subset of these solutions admits a Euclidean continuation compatible with a holographic interpretation developed in related work. In addition, we provide a pedagogical introduction to hypersurfaces in general relativity and a practical framework for constructing thin-shell spacetimes. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) On Intersecting Conformal Defects https://arxiv.org/abs/2411.14543 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2411.14543v4 Announce Type: replace Abstract: We study the physics of 2 and 3 mutually intersecting conformal defects forming wedges and corners in general dimension. For 2 defects we derive the beta function of the edge interactions for infinite and semi-infinite wedges and study them in the tricritical model in $d=3-\epsilon$ as an example. We discuss the dependency of the edge anomalous dimension on the intersection angle, connecting to an old issue known in the literature. Additionally, we study trihedral corners formed by 3 planes and compute the corner anomalous dimension, which can be considered as a higher-dimensional analog of the cusp anomalous dimension. We also study 3-line corners related to the three-body potential of point-like impurities. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Wormholes, branes and finite matrices in sine dilaton gravity https://arxiv.org/abs/2501.17091 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2501.17091v2 Announce Type: replace Abstract: We compute the double trumpet in sine dilaton gravity via WdW quantization. The wormhole size is discretized. The wormhole amplitude matches the spectral correlation of a finite-cut matrix integral, where matrices have large but finite dimensions. This strongly suggests an identification of the sine dilaton gravity theory with the q-deformed JT gravity matrix integral. At the very least, it captures all universal content of that matrix model. The disk decomposes into the physical (gauge invariant) solutions of the WdW equation, which are trumpets with discrete sizes. This decomposition modifies the usual no-boundary wavefunction to a normalizable one in sine dilaton gravity. We furthermore present an exact quantization of sine dilaton gravity with open and closed end of the world branes. These EOW branes correspond with FZZT branes for the two Liouville theories that make up sine dilaton gravity. The WdW equation implies redundancies in this space of branes, leaving a one parameter family of gauge invariant branes. One gauge choice corresponds with branes discussed by Okuyama in the context of chord diagrams and of DSSYK. Legendre transforming the EOW brane amplitude reproduces the trumpet, independent of the WdW quantization calculation. One could read our work as fleshing out the Hilbert space of closed universes in sine dilaton gravity. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) CelloAI Benchmarks: Toward Repeatable Evaluation of AI Assistants https://arxiv.org/abs/2603.01051 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01051v1 Announce Type: new Abstract: Large Language Models (LLM) are increasingly used for software development, yet existing benchmarks for LLM-based coding assistance do not reflect the constraints of High Energy Physics (HEP) and High Performance Computing (HPC) software. Code correctness must respect science constraints and changes must integrate into large, performance-critical codebases with complex dependencies and build systems. The primary contribution of this paper is the development of practical, repeatable benchmarks that quantify LLM performance on HEP/HPC-relevant tasks. We introduce three evaluation tracks -- code documentation benchmarks measure the ability of an LLM to generate Doxygen-style comments, code generation benchmarks evaluate end-to-end usability on representative GPU kernels, and graphical data analysis benchmarks evaluate vision-enabled LLMs. These benchmarks provide a unified framework for measuring progress in scientific coding assistance across documentation quality, code generation robustness, and multimodal validation analysis. By emphasizing repeatability, automated scoring, and domain-relevant failure modes, the suite enables fair comparisons of models and settings while supporting future work on methods that improve reliability for HEP/HPC software development. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Gluon Sivers function in dijet production at the EIC https://arxiv.org/abs/2603.00375 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00375v1 Announce Type: cross Abstract: The transverse-momentum-dependent (TMD) factorization theorem for dijet production in deep-inelastic scattering is used here to make predictions of the gluon Sivers function. We revise the previously studied unpolarized case and develop the formalism for a transversely polarized target. We study the impact of TMD evolution in two different schemes and we use the current extractions of the evolution kernel at N$^3$LO to make predictions for the future Electron-Ion Collider (EIC). The results strongly depend on the TMD gluon distributions and their evolution kernel. Big values of the Sivers asymmetry at the EIC are predicted, between 5-50$\%$ High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Modified Teukolsky formalism: Null testing and numerical benchmarking https://arxiv.org/abs/2603.01456 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01456v1 Announce Type: cross Abstract: Next-generation gravitational-wave detectors will make black-hole ringdown an increasingly sensitive probe of small departures from General Relativity in the strong-field regime. This motivates obtaining high-precision predictions of gravitational effective field theory, as spectral shifts can be quite small. Here we perform a focused stress test of the modified-Teukolsky framework by designing two null diagnostics. First, we consider an action with redundant operators that must produce zero first-order vacuum QNM shifts. Second, we exploit a Ricci-flat identity relating two physical cubic Riemann to test such a relation is satisfied by the ringdown spectra obtained. We compute the shifts using two independent numerical approaches: the eigenvalue-perturbation and generalized continued-fraction (Leaver-type) methods. Both null tests are passed across multiple multipoles and overtones, and the control-operator results agree in magnitude with the benchmark values reported in Ref. [1]. These validations support using the framework for obtaining accurate precitions for robust strong-field tests, with straightforward extensions to rotating backgrounds and coupling with matter fields. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Instantons In A Symmetric Quartic Potential https://arxiv.org/abs/2603.00652 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00652v1 Announce Type: cross Abstract: We extend the semi-classical analysis of the double-well potential to a quartic system featuring four degenerate minima. Utilizing the Feynman path integral in imaginary time, we identify longitudinal, transverse, and diagonal instanton configurations that mediate tunneling between minima. The zero mode is handled by transforming to a rotating frame whose origin lies on the classically determined path. By generalizing the dilute instanton gas approximation to account for these distinct pathways, we derive the coherent Rabi-type oscillations and the energy splittings of the four lowest-lying states. These semi-classical results are validated against high-precision numerical diagonalization, showing excellent agreement in the deep semi-classical limit. We further identify a critical coupling regime where the discrete $D_4$ symmetry undergoes a `melting' transition into a continuous $O(2)$ rotational symmetry, signaling a fundamental breakdown of the localized instanton description. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Proliferation transitions from a topological phase in $2+1$ dimensions https://arxiv.org/abs/2603.00245 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.00245v1 Announce Type: cross Abstract: We consider phase transitions out of a general topological phase in $2+1$ dimensions. We assume that the transition is triggered by a single Abelian anyon, which becomes light near the transition and whose worldlines proliferate after the transition. (This proliferation is often referred to as ``condensation.'') We describe the transition using a continuum field theory obtained by coupling the corresponding topological quantum field theory (TQFT) to a single complex scalar field associated with this anyon. With these assumptions, we find the most general relativistic field theory for such a transition. Even though for a given TQFT and a choice of anyon, there are infinitely many such field theories, the transition theory depends on only a single additional integer parameter. We analyze all these theories, their global symmetries, and their phases. In generic cases, the theory after the transition can be related to the original one via an Abelian hierarchy construction. In special cases, the theory after the transition is gapless, and with a particular deformation, it is related to the original TQFT by gauging an anomaly-free one-form global symmetry. We also explore the enrichment of this setup by a global U(1) symmetry. In some cases, enriching the original TQFT is incompatible with the full transition theory. Finally, we demonstrate our construction with many specific examples. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Critical Temperature(s) of Sierpinski Carpet(s) https://arxiv.org/abs/2512.20295 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2512.20295v2 Announce Type: replace-cross Abstract: We present a key algorithmic improvement to the generalized combinatorial Feynman--Vdovichenko method for calculating the critical temperature of the Ising model on Sierpinski carpets $SC_k(a,b)$, originally introduced in arxiv:1505.02699. By reformulating the method in terms of purely real-valued transfer matrices, we substantially reduce their dimension. This optimization, together with modern computational resources, enables us to reach generation $k=10$ for the canonical $SC_k(3,1)$ carpet. Extrapolation from these data yields the most accurate estimate to date of the critical temperature $T_c^{(3,1)} = 1.4782927(26)$. We further extend the analysis to additional members of the $SC_k(a,b)$ family and report their corresponding critical temperatures. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Continuum limit of a qubit-regularized SU(3) lattice gauge theory with glueballs https://arxiv.org/abs/2603.01215 Tue, 03 Mar 2026 00:00:00 -0500 arXiv:2603.01215v1 Announce Type: new Abstract: We show that a simple qubit-regularized $\mathrm{SU}(3)$ lattice gauge theory (LGT) on a plaquette chain admits a continuum limit with massive glueball excitations, providing a minimal toy model of strong interactions without quarks. By mapping the plaquette-chain Hamiltonian to the three-state quantum clock model in a magnetic field, we demonstrate that the theory can be tuned to a continuum limit governed at short distances by the $\mathbb{Z}_3$ parafermion conformal field theory (CFT), which serves as the ultraviolet (UV) fixed point. A small relevant magnetic perturbation then drives the system to a massive continuum quantum field theory in the infrared (IR). The resulting relativistic massive particles can be interpreted as quasi one-dimensional analogues of glueballs. In the continuum theory we compute the ratio of the lowest glueball masses with opposite charge conjugation to be $m^{-}/m^{+} = \,1.459(2)$ and find $\sqrt{\sigma}/m^{+}\,= 0.2648(2)$, where $\sigma$ is the string tension between a static quark and antiquark. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Precision Studies and Searches for CP Asymmetries in the Inclusive Decay $\Lambda_{c}^{+}\to \Lambda X$ https://arxiv.org/abs/2602.24089 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.24089v1 Announce Type: new Abstract: Based on $e^+e^-$ annihilation data collected with the BESIII detector at center-of-mass energies from 4.600 to 4.699 GeV, corresponding to an integrated luminosity of 4.5 fb$^{-1}$, we present the first measurement of the longitudinal polarization of $\Lambda$ hyperons produced in the inclusive decay $\Lambda_c^+ \to \Lambda X$, where $X$ denotes any allowed final state. The polarizations are determined to be $\mathcal{P}_{\Lambda} = -0.393 \pm 0.055_{\mathrm{sta.}} \pm 0.020_{\mathrm{sys.}}$ and $\mathcal{P}_{\bar{\Lambda}} = 0.288 \pm 0.056_{\mathrm{sta.}} \pm 0.017_{\mathrm{sys.}}$. We then search for CP violation using an asymmetry constructed from the $\Lambda$ polarization and the $\Lambda \to p \pi^-$ decay asymmetry parameters, and obtain $\mathcal{A}_{\mathrm{CP}}^{\mathrm{pol}} = 0.15 \pm 0.12_{\mathrm{sta.}} \pm 0.04_{\mathrm{sys.}}$. We also perform an updated measurement of the absolute branching fraction, resulted as $\mathcal{B}(\Lambda_c^+ \to \Lambda X) = (38.07 \pm 0.38_{\mathrm{sta.}} \pm 0.49_{\mathrm{sys.}})\%$, with precision improved by a factor of four relative to the current world average. A search for direct CP violation yields $\mathcal{A}_{\mathrm{CP}}^{\mathrm{dir}} = (1.5 \pm 1.0_{\mathrm{sta.}} \pm 1.0_{\mathrm{sys.}})\%$. No evidence for CP violation in inclusive charm baryon decays is observed. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Measurement of Born Cross Sections for $e^+e^-\to\Sigma^-\bar\Sigma^+$ at $\sqrt{s}=3.51-4.95$ GeV and Observation of $\psi(3770)\to\Sigma^-\bar\Sigma^+$ https://arxiv.org/abs/2602.23835 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.23835v1 Announce Type: new Abstract: Using $e^+e^-$ collision data corresponding to an integrated luminosity of 44 fb$^{-1}$ collected with the BESIII detector at the BEPCII collider, we report the first measurement of Born cross sections and effective form factors for $e^+e^-\to\Sigma^-\bar\Sigma^+$ at centre-of-mass energies between 3.51 and 4.95 GeV. With a fit to the $\sqrt{s}$-dependent dressed cross sections, the decay $\psi(3770)\to\Sigma^-\bar\Sigma^+$ is observed for the first time with a significance of 5.5$\sigma$, including systematic uncertainties. Upper limits at the 90\% confidence level on the product of the branching fraction and the electronic partial width are provided for other possible charmonium(-like) states. The ratios of Born cross sections for the $\Sigma$ isospin-triplet states are determined and can be used to test the vector-meson-dominance model. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) End-to-end Differentiable Calibration and Reconstruction for Optical Particle Detectors https://arxiv.org/abs/2602.24129 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.24129v1 Announce Type: new Abstract: Large-scale homogeneous detectors with optical readouts are widely used in particle detection, with Cherenkov and scintillator neutrino detectors as prominent examples. Analyses in experimental physics rely on high-fidelity simulators to translate sensor-level information into physical quantities of interest. This task critically depends on accurate calibration, which aligns simulation behavior with real detector data, and on tracking, which infers particle properties from optical signals. We present the first end-to-end differentiable optical particle detector simulator, enabling simultaneous calibration and reconstruction through gradient-based optimization. Our approach unifies simulation, calibration, and tracking, which are traditionally treated as separate problems, within a single differentiable framework. We demonstrate that it achieves smooth and physically meaningful gradients across all key stages of light generation, propagation, and detection while maintaining computational efficiency. We show that gradient-based calibration and reconstruction greatly simplify existing analysis pipelines while matching or surpassing the performance of conventional non-differentiable methods in both accuracy and speed. Moreover, the framework's modularity allows straightforward adaptation to diverse detector geometries and target materials, providing a flexible foundation for experiment design and optimization. The results demonstrate the readiness of this technique for adoption in current and future optical detector experiments, establishing a new paradigm for simulation and reconstruction in particle physics. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Extracting a Toponium Signal at the LHC with Spin and Quantum Information Tools https://arxiv.org/abs/2602.23426 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.23426v1 Announce Type: cross Abstract: We investigate near-threshold top-antitop production at the LHC, focusing on the impact of toponium formation on spin correlations and quantum information properties of the final state. Considering the top-antitop system as a mixed two-qubit state, we reconstruct spin density matrices via quantum tomography and evaluate several observables including some inspired by quantum information. We then compare their sensitivity in discriminating toponium effects from top-antitop production without these effects. Our results demonstrate that combining these variables is expected to significantly enhance sensitivity to toponium effects, bringing new ways to explore these subtle features. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Characterization of UV optical components for photon detector calibration in liquid argon TPCs https://arxiv.org/abs/2602.23563 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.23563v1 Announce Type: cross Abstract: Large liquid argon time projection chambers (LArTPCs) require stable and well-characterized delivery of ultraviolet (UV) light for in situ calibration of photosensors at cryogenic temperatures. This article reports bench-top and cryogenic measurements of the optical components used in a UV light calibration system, including multi-mode fused-silica fibers, SMA-to-SMA connectors, optical fiber feedthroughs, and light-diffuser assemblies. Light loss in several fiber types and SMA connectors was measured across wavelengths from \qtyrange{275}{970}{nm}. In addition, light-loss measurements of the tested fibers after several liquid-nitrogen thermal cycles showed no statistically significant degradation relative to baseline measurements, and high-rate pulsed exposure (30-90 million pulses from a \qty{275}{nm} LED) likewise showed no measurable aging in jacketed fibers. A compact, palm-sized, 3D-printed PEEK diffuser housing with stacked UV-grade fused-silica diffusers yields Lambertian emission and the most uniform angular distribution. Optical components exhibiting improved UV transmission were deployed successfully in multiple DUNE small- and large-scale prototypes, demonstrating reliable operation of UV light calibration systems. These findings inform component selection and calibration procedures for achieving reliable, uniform UV light delivery in large-scale cryogenic detectors such as DUNE. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Design of a high voltage delivery system for noble liquid time projection chambers https://arxiv.org/abs/2602.23564 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.23564v1 Announce Type: cross Abstract: Noble liquid time projection chambers (TPCs) are a leading technology in the detection of ionizing radiation, particularly in applications such as accelerator neutrino physics, dark matter detection, and neutrinoless double beta decay. This paper addresses the design considerations for implementing stable high voltage (HV) systems within large noble liquid TPCs, with a focus on the nEXO experiment. Utilizing insights from prior HV research and experimental investigations, we outline factors influencing HV stability and discuss design choices to improve stability and prevent electrical discharges. A novel HV delivery system concept is presented, tailored for the nEXO TPC, which incorporates these design considerations while also meeting the stringent radiopurity requirements of the nEXO neutrinoless double beta decay search. These design considerations and their specific implementation towards a HV delivery system offer guidance to future experiments applying high voltage in noble liquid environments. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Kaons ($K^\pm$) in hot and dense QCD https://arxiv.org/abs/2602.24170 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.24170v1 Announce Type: cross Abstract: We present a systematic QCD sum-rule analysis of the in-medium properties of the charged kaon doublet $K^{\pm}$ over the full $(T,\rho)$ plane relevant to current and forthcoming heavy-ion experiments. Working within the QCD sum-rule framework and incorporating temperature-and density-dependent quark, gluon, and mixed condensates, we derive Borel-transformed sum rules for the effective masses $m_{K^{\pm}}$, the pseudoscalar decay constants $f_{K^{\pm}}$, and the vector self-energy $\Sigma_{v}$ of both charged states simultaneously. Our vacuum results, $m_{K^{-}} = 494.6^{+4.9}_{-6.9}$~MeV and $f_{K^{-}} = 157.3^{+4.1}_{-2.9}$~MeV (with near-degenerate $K^{+}$ values), are in excellent agreement with Particle Data Group values at the sub-percent level. In the medium, $m_{K^{\pm}}$ decreases monotonically with increasing baryon density and temperature, signalling progressive partial restoration of chiral symmetry. A pronounced mass splitting $\Delta m = m_{K^{-}} - m_{K^{+}}$ develops in baryonic matter, driven by the opposite sign of the Weinberg--Tomozawa vector interaction for the two charge states; it reaches $|\Delta m| \sim 0.35$~GeV near $\rho \simeq 3.2\,\rho_{\rm sat}$ at $T = 0$ and is partially quenched by thermal fluctuations. A central outcome of this study is the extraction of the critical onset density $\rho_c$, defined as the threshold beyond which the in-medium modifications of $K^{-}$ properties signal the onset of the transition toward the chirally restored phase. We stress that $\rho_c(T)$ should not be interpreted as a precise determination of the QCD critical point-a task beyond the reach of any current effective framework-but rather as an indicator .... High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Unfolding without Iterations, Adversaries, or Surrogates https://arxiv.org/abs/2602.24282 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.24282v1 Announce Type: cross Abstract: Correcting measurements for detector effects and constructing appropriate public data representations is a pressing problem in LHC physics. Current methods solve this inverse problem by relying on iterations, minimax optimization, or a surrogate forward mapping. We introduce Adversary-free Unfolding SanS Iteration or Emulation (AUSSIE), which dispenses with these mechanisms while remaining asymptotically correct. AUSSIE replaces the second OmniFold step with a new loss function that directly yields solutions with minimal dependence on the reference simulation. We showcase AUSSIE on various unfolding tasks, including full-phase-space jet substructure. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Long term study of sedimentation and biofouling at Cascadia Basin, the site of the Pacific Ocean Neutrino Experiment https://arxiv.org/abs/2507.09086 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2507.09086v4 Announce Type: replace Abstract: STRings for Absorption Length in Water (STRAW)-a and b were pathfinder instruments deployed to characterize the anticipated site of the Pacific Ocean Neutrino Experiment (P-ONE), which is a future neutrino telescope that will be located in the North Pacific Ocean. Measurements of the evolution of the optical transmission efficiency from STRAW-a showed a decline over the detector's lifetime for the upward-facing modules. Video footage of the pathfinders strongly suggested this decline was caused by biofouling and sedimentation. We measure the effect of biofouling and sedimentation to be a decrease in the transparency of upward-facing optical surfaces over 5 years of operations. A majority of downward-facing optical surfaces, which will dominate P-ONE's sensitivity to astrophysical sources, showed no visible biofouling. Extrapolations motivated by biological growth models estimated that these losses started around 2.5 years after deployment, and suggest a reduction in transparency ranging from 35$\%$ of the original to complete obscuration for the upward-facing modules. Samples of biofouling were taken in order to identify the microbial diversity of these organisms and inform potential intervention strategies. Results of the microbial samples and a candidate anti-biofouling strategy that will be tested on upcoming P-ONE instruments are discussed. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) The role of final-state interaction modeling in neutrino energy reconstruction and oscillation measurements https://arxiv.org/abs/2511.03964 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2511.03964v2 Announce Type: replace Abstract: We present a quantitative demonstration that, without additional theoretical and experimental efforts, realistic variations in final-state-interaction (FSI) modeling may alter reconstructed neutrino-energy spectra at next-generation long-baseline experiments by amounts comparable to, or larger than, variations induced by oscillation-parameter shifts at their projected precision. Using the DUNE flux and baseline as a case study, we show that these FSI-driven distortions can mimic the effects of changes in the oscillation parameters $\Delta m^2_{32}$ or $\delta_{\rm CP}$, producing a potential degeneracy. Our analysis thereby underscores the urgent need for an improved characterisation of FSI to enable robust constraints from near detectors through the development of theory-driven uncertainty parameterisations benchmarked with dedicated new measurements. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) NuBench: An Open Benchmark for Deep Learning-Based Event Reconstruction in Neutrino Telescopes https://arxiv.org/abs/2511.13111 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2511.13111v3 Announce Type: replace Abstract: Neutrino telescopes are large-scale detectors designed to observe Cherenkov radiation produced from neutrino interactions in water or ice. They exist to identify extraterrestrial neutrino sources and to probe fundamental questions pertaining to the elusive neutrino itself. A central challenge common across neutrino telescopes is to solve a series of inverse problems known as event reconstruction, which seeks to resolve properties of the incident neutrino, based on the detected Cherenkov light. In recent times, significant efforts have been made in adapting advances from deep learning research to event reconstruction, as such techniques provide several benefits over traditional methods. While a large degree of similarity in reconstruction needs and low-level data exists, cross-experimental collaboration has been hindered by a lack of diverse open-source datasets for comparing methods. We present NuBench, an open benchmark for deep learning-based event reconstruction in neutrino telescopes. NuBench comprises seven large-scale simulated datasets containing nearly 130 million charged- and neutral-current muon-neutrino interactions spanning 10 GeV to 100 TeV, generated across six detector geometries inspired by existing and proposed experiments. These datasets provide pulse- and event-level information suitable for developing and comparing machine-learning reconstruction methods in both water and ice environments. Using NuBench, we evaluate four reconstruction algorithms - ParticleNeT and DynEdge, both actively used within the KM3NeT and IceCube collaborations, respectively, along with GRIT and DeepIce - on up to five core tasks: energy and direction reconstruction, topology classification, interaction vertex prediction, and inelasticity estimation. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) MEDIC: a network for monitoring data quality in collider experiments https://arxiv.org/abs/2511.18172 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2511.18172v2 Announce Type: replace Abstract: Data Quality Monitoring (DQM) is a crucial component of particle physics experiments and ensures that the recorded data is of the highest quality, and suitable for subsequent physics analysis. Due to the extreme environmental conditions, unprecedented data volumes, and the sheer scale and complexity of the detectors, DQM orchestration has become a very challenging task. Therefore, the use of Machine Learning (ML) to automate anomaly detection, improve efficiency, and reduce human error in the process of collecting high-quality data is unavoidable. Since DQM relies on real experimental data, it is inherently tied to the specific detector substructure and technology in operation. In this work, a simulation-driven approach to DQM is proposed, enabling the study and development of data-quality methodologies in a controlled environment. Using a modified version of Delphes -- a fast, multi-purpose detector simulation -- the preliminary realization of a framework is demonstrated which leverages ML to identify detector anomalies as well as localize the malfunctioning components responsible. We introduce MEDIC (Monitoring for Event Data Integrity and Consistency), a neural network designed to learn detector behavior and perform DQM tasks to look for potential faults. Although the present implementation adopts a simplified setup for computational ease, where large detector regions are deliberately deactivated to mimic faults, this work represents an initial step toward a comprehensive ML-based DQM framework. The encouraging results underline the potential of simulation-driven studies as a foundation for developing more advanced, data-driven DQM systems for future particle detectors. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Electron identification and hadron discrimination using Cherenkov radiation in air and SiPMs https://arxiv.org/abs/2601.03405 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2601.03405v2 Announce Type: replace Abstract: This paper presents a method to identify electrons using the Cherenkov light emitted when a charged particle travels in air and photons are detected with a Silicon PhotoMultiplier (SiPM). The analysis is based on a photon-counting approach using SPAD cells and uses data collected during a test beam at CERN PS. The results are well described by a simple Monte Carlo simulation, which further demonstrates that a very good electron identification and a strong pion/hadron rejection could be obtained over a wide momentum range. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Data-driven core collapse supernova multilateration with first neutrino events https://arxiv.org/abs/2410.11984 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2410.11984v3 Announce Type: replace-cross Abstract: A Galactic core-collapse supernova (CCSN) is likely to be observed in neutrino detectors around the world minutes to hours before the electromagnetic radiation arrives. The SNEWS2.0 network of neutrino and dark matter detectors aims to use the relative arrival times of the neutrinos at the different experiments to point back to the supernova so as to facilitate follow-up observation. One of the simplest methods to estimate the CCSN direction is to use the first neutrino events detected through the inverse beta decay (IBD) process, $\overline{\nu}_e p\rightarrow e^+n$. We will consider neutrino detectors sensitive to IBD interactions with low backgrounds. The difference in signal arrival times between a large and a small detector will be biased, however, with the first event at the smaller detector, on average, arriving later than that at the larger detector. This bias can be mitigated by using these first events in a data-driven approach without recourse to simulations or models. The resulting method requires, at minimum, only the times of the first events at most detectors, along with a longer time series of events from one larger detector to act as a reference lightcurve. In this article, we demonstrate this method and its uncertainty estimate using pairs of detectors of different sizes and with different supernova distances. Finally, we use this method to calculate probability skymaps using four detectors currently in operation (Super-Kamiokande, JUNO, LVD, and SNO+) and show that the calculated probabilities yield appropriate confidence intervals for all supernova directions. The area of the 68\% confidence interval varies by distance and direction, but is expected to be a few thousand square degrees. The resulting skymaps should be useful for the multi-messenger community as a rapid, initial pointing to follow up on the SNEWS2.0 Galactic CCSN neutrino alert. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Probing Cosmic Neutrino Background through Parametric Fluorescence https://arxiv.org/abs/2507.10868 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2507.10868v3 Announce Type: replace-cross Abstract: We point out that relic neutrinos from the Big Bang may induce the parametric fluorescence in atomic or molecular systems, which offers a novel way to discover cosmic neutrino background. By coherently scattering with molecular energy levels, a massive neutrino can spontaneously ``decay" into a lighter neutrino and an infrared signal photon, i.e., $\nu^{}_{i} + M \to \nu^{}_{j} + \gamma^{}_{\rm S} + M$, where the molecular state $M$ remains unchanged after the scattering. Because the amplitudes of different radiants are matched in phase, the rate is coherently enhanced and proportional to the squared density of ambient dipoles. When the energy transfer from neutrinos coincides with the energy-level difference, the fluorescence will be on resonance. Near the resonance, the rate is proportional to the square of the coherence time $T^{}_{\rm c}$ of the ensemble. For a nominal target volume of $5~{\rm m^3}$ (or $5~{\rm cm^3}$), the signal rate can reach $1~{\rm yr}^{-1}$ for $T^{}_{\rm c} = 10~{\rm ns}$ (or $T^{}_{\rm c} = 10~{\rm \mu s}$). This event rate appears to be very promising in consideration of an even longer coherence time that is achievable in solid systems. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Gas Electroluminescence in a Dual Phase Xenon-Doped Argon Detector https://arxiv.org/abs/2510.02261 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2510.02261v2 Announce Type: replace-cross Abstract: Noble element detectors using argon or xenon as the detection medium are widely used in the searches for rare neutrino and dark matter interactions. Xenon doping in liquid argon can preserve attractive properties of an argon target while enhancing the detectable signals with properties of xenon. In this work, we deployed a dual-phase liquid argon detector with up to 4% xenon doping in the liquid and studied its gas electroluminescence properties as a function of xenon concentration. At $\sim$2% xenon doping in liquid argon, we measured $\sim$34 ppm of xenon in the gas and observed $\sim$2.5 times larger electroluminescence signals in the detector than those in pure argon. By analyzing signals recorded by photosensors of different wavelength sensitivities, we confirm that the argon gas electroluminescence process is strongly affected by the addition of xenon. We propose an analytical model to describe the underlying energy transfer mechanism in argon-xenon gas mixtures. Lastly, the implications of this measurement for low energy ionization signal detection will be discussed. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) An ultrafast plenoptic-camera system for high-resolution 3D particle tracking in unsegmented scintillators https://arxiv.org/abs/2511.09442 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2511.09442v4 Announce Type: replace-cross Abstract: Neutrino detectors, particle calorimeters and some dark matter detectors require dense and massive active materials. An extremely fine segmentation is desirable to achieve precise three-dimensional particle tracking. However, such systems introduce significant challenges in construction and demand a large number of readout electronics channels, leading to extremely high costs. In this article, we propose an alternative approach to elementary particle detection that enables ultrafast three-dimensional high-resolution imaging in large volumes of unsegmented scintillator. Enabling technologies are plenoptic systems and time-resolving single-photon avalanche diode array imaging sensors. Together, they enabled us, using a plenoptic camera, to reconstruct the origin of single photons in the scintillator. A case study focused on neutrino detection demonstrates full event reconstruction with a spatial resolution of two hundred micrometres. This work paves the way for a class of particle detectors whose capabilities should be further enhanced through future developments and expanded to Cherenkov light detection, medical imaging and neutron detection. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Closepacking effects on strangeness and baryon production at the LHC https://arxiv.org/abs/2512.00671 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2512.00671v2 Announce Type: replace-cross Abstract: Data from the LHC show a rise in strange-hadron production with charged-particle multiplicity in pp collisions. The Monte-Carlo event generator PYTHIA, using its default Monash tune, instead predicts constant strangeness. We investigate a mechanism invoked during hadronization called string closepacking, where overlapping strings generate a background field, here assumed to be predominantly aligned with the beam axis. This increases the effective string tension, reducing strangeness suppression and thus enhancing strangeness production. We tune this model to LHC data and contrast it with several alternatives. We comment specifically on the challenge of simultaneously describing the non-strange p/pi ratio, and introduce a mechanism which may act to suppress it. Many of the salient particle-production ratios can be qualitatively described by this model, although the XiC/D ratio and the shape of pT spectra remain challenging to account for. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Finite-temperature Sp(4) Yang-Mills theory: towards the continuum https://arxiv.org/abs/2602.23735 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.23735v1 Announce Type: new Abstract: We present numerical results obtained in a finite-temperature study of the Sp(4) Yang-Mills theory on the lattice. We study its first-order confinement/deconfinement phase transition, by reconstructing the density of states via the Logarithmic Linear Relaxation (LLR) algorithm. We perform our measurements on lattices with different extents of space and time (and aspect ratios). We estimate the size of discretisation and finite-volume artefacts. We find clear signatures of a first-order transition. We determine the critical coupling, the specific heat, and the surface tension, for finite extents of the thermal circle, and use the results to set bounds for the continuum theory. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) A novel gauge-equivariant neural-network architecture for preconditioners in lattice QCD https://arxiv.org/abs/2602.23840 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.23840v1 Announce Type: new Abstract: Lattice QCD simulations are computationally expensive, with the solution of the Dirac equation being the major computational bottleneck of many calculations. We introduce a novel gauge-equivariant neural-network architecture for preconditioning the Dirac equation in the regime where critical slowing down occurs. We study the behavior of this preconditioner as a function of topological charge and lattice volume and show that it mitigates critical slowing down. We also show that this preconditioner transfers to unseen gauge configurations without any retraining, therefore enabling applications not possible with competing methods. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Baryon masses with C-periodic boundary conditions https://arxiv.org/abs/2602.23910 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.23910v1 Announce Type: new Abstract: Isospin-breaking corrections pose a significant challenge to lattice simulations, both because of the splitting between the up and down quark masses and, in particular, the need to include QED effects. The RC* collaboration has developed the openQxD code, based on openQCD, which enables fully dynamical QCD+QED simulations through the implementation of C-periodic boundary conditions. We use this code to measure baryon masses, with a special focus on the {\Omega^-} baryon mass, whose precise determination is especially important since it has been used to set the scale of lattice simulations. Due to the use of C-periodic boundary conditions, the two-point function of the {\Omega^-} baryon gets additional partially connected contributions, which vanish in the infinite-volume limit and which we are computing for the first time. We will present preliminary results for baryon masses obtained on QCD ensembles with C-periodic boundary conditions, at an unphysical pion mass of approximately 400 MeV. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Electromagnetic form factors and structure of the $T_{bb}$ tetraquark https://arxiv.org/abs/2602.24000 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.24000v1 Announce Type: new Abstract: We present the first lattice QCD calculation of electromagnetic form factors of a tetraquark, focusing on the $T_{bb} = bb\bar u \bar d$ with quantum numbers $I(J^P) = 0(1^+)$. The electromagnetic current probes the charge monopole, magnetic dipole and the electric quadrupole distributions within the tetraquark. From it, we find evidence that its structure consists of a compact heavy diquark $[bb]$ in spin one, color-antitriplet configuration, and a light antidiquark $[\bar u \bar d]$ in spin zero, color-triplet configuration. The computations were performed on a single CLS ensemble with $N_f = 2+1$ dynamical quarks at a lattice spacing $a\approx 0.064$ fm and with a pion mass $m_\pi \approx 290$ MeV. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Isospin breaking corrections to the hadronic vacuum polarization with stochastic coordinate sampling https://arxiv.org/abs/2602.24132 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.24132v1 Announce Type: new Abstract: In the recent Muon g-2 Theory Initiative white paper update, the hadronic vacuum polarization (HVP) contribution -- which dominates the theoretical uncertainty -- is evaluated as an average of different lattice QCD calculations. Since lattice simulations are mostly carried out in isospin symmetric QCD, corrections due to the mass difference of the up and down quarks and the coupling to photons have to be accounted for. These isospin breaking effects are of order 1\% and can be treated as corrections to the result for the HVP contribution in isospin symmetric QCD. In the current estimate of the HVP contribution, these effects are a large source of uncertainty due to the extensive computational cost to compute all occurring Wick contractions and degrading signal-to-noise behaviour especially for quark disconnected diagrams. We present the current status of the calculation of isospin breaking corrections in the HVP contribution for the RBC/UKQCD collaborations. We use a dataset of propagators computed using stochastic coordinate sampling (SCS) to construct all necessary Wick contractions for the electromagnetic and strong isospin breaking effects. We employ different versions of QED on the lattice, such as QED$_L$, QED$_r$ and QED$_\infty$ to improve our estimate of finite-volume uncertainties. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) The three-loop hadronic vacuum polarization in chiral perturbation theory https://arxiv.org/abs/2602.24184 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.24184v1 Announce Type: new Abstract: Hadronic vacuum polarization is a key observable in low-energy QCD, and is famously the greatest contributor to the theoretical uncertainty in the muon magnetic moment. Its long-distance part in particular is a weak point of the current best lattice QCD computations. In this summary of our recent work, we present its computation to next-to-next-to-next-to-leading order in chiral perturbation theory, capturing the lowest-energy hadronic contributions to unprecedented precision and opening the door for improved control over lattice finite volume effects. The result depends on a small number of low-energy constants, whose values are mostly under good control. This calculation pushes the envelope of high-order chiral perturbation theory and of the evaluation of multiloop integrals with massive propagators, thereby extending the toolbox for precision calculations in very low-energy QCD. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) The Light Quark Connected Hadronic Vacuum Polarization Contribution to the muon anomaly via Sparsened Meson Fields https://arxiv.org/abs/2602.24190 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.24190v1 Announce Type: new Abstract: We present an update on our determination of the light-quark connected contribution to the hadronic vacuum polarization (HVP) of the muon anomalous magnetic moment, $a_\mu$, on a finer lattice with 2+1+1 highly-improved staggered quark (HISQ) ensemble from the MILC collaboration with physical pion mass, 0.042 fm lattice spacing, and size $144^3 \times 288$ sites. Within the low-mode averaging (LMA) framework, the HVP correlator is decomposed into low-low (LL), high-low (HL), low-high (LH) and high-high (HH) components. Since the LL part dominates the total statistical uncertainty but is also the most computationally expensive to evaluate, we implement a sparsening strategy to construct the meson fields efficiently. This approach significantly reduces the computational cost while preserving signal quality. By combining the sparsened LL contribution with HL, LH and HH components, we achieve an improved determination of the light-quark connected HVP contribution to $a_\mu$. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Progress on computing the hadronic vacuum polarization contribution to the muon anomalous magnetic moment with staggered fermions https://arxiv.org/abs/2602.24200 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.24200v1 Announce Type: new Abstract: We give an update of our calculation of the light-quark, connected, hadronic vacuum polarization contribution to the muon anomalous magnetic moment, or muon $g-2$. The update includes preliminary results on a $2 + 1 + 1$ highly-improved staggered quark (HISQ) ensemble from the MILC collaboration with physical pion mass, $0.042$ fm lattice spacing, and volume $144^3 \times 288$. We discuss code and algorithm improvements for these calculations to compute the vector-vector correlation function more efficiently. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Low-energy interactions between doubly charmed baryons and Goldstone bosons from lattice QCD https://arxiv.org/abs/2511.12611 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2511.12611v2 Announce Type: replace Abstract: We perform a lattice QCD calculation of the $S$-wave interactions between the ground-state spin-$1/2$ doubly charmed baryons and Goldstone bosons. The lattice QCD simulations are carried out on four $2+1$ flavor Wilson-Clover ensembles generated by the CLQCD collaboration, with a lattice spacing $a=0.07746$ fm and two different pion masses, $M_\pi \sim 210$ and $\sim 300~\mathrm{MeV}$. Energy levels are extracted for four single channels, $\Omega_{cc}\bar{K}^{(-2,1/2)}$, $\Xi_{cc}K^{(1,1)}$, $\Xi_{cc}K^{(1,0)}$, and $\Xi_{cc}\pi^{(0,3/2)}$, where the superscripts $(S,I)$ denote strangeness $S$ and isospin $I$. Our results indicate that the $\Xi_{cc}K^{(1,0)}$ channel is attractive, exhibiting negative energy shifts relative to the non-interacting two-hadron thresholds, while the other three channels are repulsive. Using L\"uscher's finite-volume formula, we extract the near-threshold phase shifts and determine the $S$-wave scattering lengths. Furthermore, a virtual state pole is found in the $\Xi_{cc}K^{(1,0)}$ scattering amplitude. These results provide {\it ab initio} input to enable high-precision studies of the properties and spectroscopy of doubly heavy baryons. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Hadronic vacuum polarization to three loops in chiral perturbation theory https://arxiv.org/abs/2510.12885 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2510.12885v2 Announce Type: replace-cross Abstract: Hadronic vacuum polarization at low virtualities limits the precision of experimental tests of the standard model via important physical observables. Here we compute that effect in two-flavor chiral perturbation theory to three loops. Among the master integrals that describe the amplitude, six are elliptic functions of the momentum. Of these five are new to this work, although all can be related to the three-loop sunset integral. The renormalizability of the amplitude hinges on relations between the master integrals that were not previously known and that are not consequences of the integration-by-parts reduction. Our result is intended to serve as a starting point for phenomenological calculations, as well as the computation of finite-volume corrections in lattice QCD. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Integrability breaking in semiclassical strings in Koopman-Krylov space https://arxiv.org/abs/2602.23421 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.23421v1 Announce Type: new Abstract: While very powerful, integrability in semiclassical string solutions is known to be a rare property. Motivated by the need to understand and characterise the large landscape of non-integrable string dynamics, we extend Krylov methods for probing chaos to classical systems. We introduce a Koopman-Krylov framework, formulated in the Koopman-von Neumann description of classical mechanics and implemented via a generator extended dynamic mode decomposition (gEDMD) approximation of the Koopman generator acting on observables. Using this framework, we study how integrability-breaking deformations of integrable string dynamics induce characteristic redistributions of spectral weight, leading to observable-dependent delocalisation and spreading in Krylov space. We illustrate the Koopman-Krylov diagnostics across three classes of non-integrable semiclassical string solutions. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Lightcone Bootstrap for Multipoint Defect Correlators https://arxiv.org/abs/2602.23428 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.23428v1 Announce Type: new Abstract: We initiate the lightcone bootstrap analysis of multipoint correlators in a defect conformal field theory. The setup we consider is the three-point function of two bulk and one defect operator. Requiring consistency of the crossing equation in the lightcone limit, we find constraints on the defect spectrum at large transverse spin. Specifically, to reproduce the exchange of the leading-twist operator in the bulk channel we find two new twist-accumulating families of defect operators at large transverse spin and we compute their defect CFT data in this limit. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) A Menagerie of Wormholes and Cosmologies in the Gravitational Path Integral https://arxiv.org/abs/2602.23432 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.23432v1 Announce Type: new Abstract: We analyse a variety of Euclidean saddles in the gravitational path integral, with asymptotic AdS boundary conditions, in a class of Einstein-Scalar-Maxwell models. These include single boundary solutions, usual and wineglass wormholes, as well as more exotic (quasi)-oscillatory saddles. We find several interesting phase transitions between these solutions. The Euclidean wormhole backgrounds can be analytically continued to Lorentzian FLRW universes. Some of them contain an early period of inflation. We delineate the conditions under which they can be the dominant saddles in the gravitational path integral and use them to estimate ratios of probabilities for different cosmological outcomes. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) General Actions of Extended Objects and Volume-Preserving Diffeomorphism https://arxiv.org/abs/2602.23443 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.23443v1 Announce Type: new Abstract: We consider actions that are general functions of the worldsheet/worldvolume metric and the induced metric for extended objects embedded in spacetime as Riemannian manifolds, areal-metric manifolds, and volume-metric manifolds. For strings on a Riemannian spacetime, we consider general actions respecting volume-preserving diffeomorphisms (VPD), general diffeomorphisms, and diffeomorphisms with Weyl symmetry, respectively. Well-known Schild, Nambu-Goto, and Polyakov actions are included as special cases. We reach two main conclusions: (1) When actions are functions of both the worldsheet metric and induced metrics, all nontrivial self-consistent actions are classically equivalent. (2) As a physical constraint on the classical action, VPD symmetry is as strong as the full diffeomorphism symmetry. The discussion is then extended to strings in spacetime manifolds equipped with the areal or volume metrics. Then, we further consider higher-dimensional extended objects in spacetime defined with areal or volume metrics, and show the equivalence between the generalized Schild actions and the generalized Nambu-Goto action. We prove a general theorem on VPD that explains this equivalence. Incidentally, while only the areal metric is needed to define the string worldsheet action, we show that the Polyakov action with an areal-metric perturbation cannot describe critical strings without other interaction terms. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Classical investigations in a CPT-even Lorentz-violating model and their implications for the Compton effect https://arxiv.org/abs/2602.23456 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.23456v1 Announce Type: new Abstract: In this work, we investigate some aspects of the Maxwell electrodynamics with the additive Lorentz-violating (LV) CPT-even term. For this model, we derive the energy and momentum conservation laws, highlighting the modifications introduced by Lorentz violation. Furthermore, using the modified dispersion relations, we analyze the correction to Compton effect arising from the presence of the LV vector. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) A 3BF model of quantum gravity coupled to Standard Model matter https://arxiv.org/abs/2602.23661 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.23661v1 Announce Type: new Abstract: We develop an explicit model of quantum gravity coupled to the matter fields of the Standard Model, based on the 3-group structure and the 3BF action, within the framework of higher gauge theory. The model is constructed by providing a rigorous definition for the path integral of the theory, achieved by defining the whole theory on a piecewise-flat spacetime manifold. To that end, we develop a method to systematically discretize both the action and the path integral measure by passing from a smooth manifold to a piecewise-flat manifold. Finally, we discuss in some detail the structure of the resulting quantum gravity model, and provide a preliminary analysis of its semiclassical limit. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Corrections of an elliptic block in the NS sector https://arxiv.org/abs/2602.24026 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.24026v1 Announce Type: new Abstract: We propose a correction to one of the elliptic blocks in the NS sector of 2d $\mathcal N = 1$ superconformal field theories. We analyze the 4-point block in the pillow geometry to demonstrate the necessity of the correction and verify the formula by numerically checking the crossing symmetries in the $\mathcal N =1 $ super Liouville theory, as well as directly comparing the $c$-recursion and $h$-recursion results. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) More on $T \overline{T}$-like deformations in higher dimensions https://arxiv.org/abs/2602.24058 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.24058v1 Announce Type: new Abstract: We investigate several possible generalisations of $T\overline{T}$ deformations to three- and higher-dimensional field theories. Starting from the two-dimensional $T\overline{T}$ flow, we work out its higher-dimensional uplift, which results in a non-local and non-isotropic three-dimensional theory. Starting instead from the relation between the Nambu-Goto action and $T\overline{T}$ in $d=2$, we study the flow equation obeyed by the Dirac-Nambu-Goto actions in $d>2$ dimensions, written in terms of the stress-energy tensor only. Similarly, we derive the stress-tensor flow obeyed by the Born-Infeld actions in $d$ dimensions and by the Dirac-Born-Infeld actions in $d=2$ and $d=3$. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Conformal symmetry in force-free electrodynamics https://arxiv.org/abs/2602.22262 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.22262v1 Announce Type: cross Abstract: It is shown that conformal symmetry exists in force-free electrodynamics (FFE) in Minkowski spacetime, a foundational framework for describing magnetospheres around astronomical objects. In force-free magnetospheres, charges are constrained to move along magnetic field lines and experience zero Lorentz force, due to the everywhere perpendicular orientation of electric and magnetic fields. However, a general angle-preserving conformal mapping of force-free fields does not necessarily produce another physically admissible force-free configuration when sources are present. In this work, we demonstrate that such invariance can nevertheless arise for certain choices of the free functions. Specifically, the governing stream equation is shown to be invariant under M\"obius transformations. This symmetry reveals a structural linkage between known solutions and, notably, maps the region inside a magnetospheric horizon (the lightsurface) of one solution to the exterior of its dual counterpart, and vice versa. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Lattice studies of entanglement entropy in $O(N)$ models at finite densities https://arxiv.org/abs/2602.22881 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.22881v1 Announce Type: cross Abstract: As a characteristic property of all quantum systems, entanglement participates in many important quantum phenomena. In this proceeding, we employ it in the study of quantum field theories at finite density. We incorporate evaluations of entanglement entropy using the replica trick into MC simulations of $O(N)$ models at finite density with the worm algorithm and present some initial results for the nonlinear $O(4)$ model in 3 dimensions. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Mimetic gravity in the extended objects framework https://arxiv.org/abs/2602.23538 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.23538v1 Announce Type: cross Abstract: Starting from the most general second-order in derivatives theories describing extended objects of arbitrary dimension evolving geodetically in a codimension-one flat ambient space-time, we determine the subset of models yielding second-order equations of motion, forming an intriguing theory known as Lovelock-type brane gravity (LBG). These models further extend the so-called geodetic brane gravity (GBG) approach, thereby naturally promoting the GBG geometric properties, allowing LBG to be reformulated as a mimetic embedding gravity and, in turn, the possibility of introducing fictional matter through a peculiar current $\mathcal{T}^{a\,\mu}$. Grounded in the elasticity theory, we provide a possible origin of such a current. Finally, variational techniques are employed to elucidate the mechanical function of both the dark current $\mathcal{T}^{a\,\mu}$ and its tangential components $\mathcal{T}^{ab}$; these serve as the constituents of a fictional energy-momentum tensor that shares characteristics with a perfect fluid. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) From quantum time to manifestly covariant QFT: on the need for a quantum-action-based quantization https://arxiv.org/abs/2602.23625 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.23625v1 Announce Type: cross Abstract: In quantum time (QT) schemes, time is promoted to a degree of freedom, allowing Lorentz covariance to be made explicit for single particles. We ask whether this can be lifted to QFT, so that Lorentz covariance becomes manifest at the Hilbert-space level, rather than being hidden as in the standard canonical formulation. We address this question by proposing a second-quantized approach in which the elementary particle is the QT particle itself, leading naturally to the notion of spacetime field algebras and of quantum action. We show, however, that a naive many-body construction runs into inconsistencies. To pinpoint their origin we introduce a classical counterpart of the second-quantized formalism, spacetime classical mechanics (SCM), and prove a no-go theorem: Dirac quantization of SCM collapses back to standard QFT and therefore hides covariance. We circumvent this problem by presenting a quantum-action--based quantization that yields a spacetime version of quantum mechanics (SQM), making covariance manifest for (interacting) QFTs. Finally, we show that this resolution is tied to a genuine spacetime generalization of the notion of quantum state, required by causality and closely connected to recent ``states over time'' proposals and, in dS/CFT-motivated settings, to microscopic notions of timelike entanglement and emergent time. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Acoustic Black Hole in Hayward Spacetime: Shadow, Quasinormal Modes and Analogue Hawking Radiation https://arxiv.org/abs/2602.23755 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.23755v1 Announce Type: cross Abstract: In this paper, we study an acoustic black hole in Hayward spacetime from the relativistic Gross-Pitaevskii theory. By examining the critical null geodesics, the shadow of the acoustic horizon is sketched. Then the quasinormal mode (QNM) frequencies of the acoustic Hayward black hole are computed numerically using the WKB method, which are shown to be more stable than those of the Hayward black hole, and the variations in the QNM frequencies are shown to correlate with the behavior of the effective potential. Moreover, the WKB method is also employed to calculate the grey-body factor and energy emission rate of the analogue Hawking radiation. It is shown that, as the tuning parameter increases, both the grey-body factor and the energy emission rate are enhanced, which can likewise be attributed to changes in the effective potential. Besides, the radius of acoustic shadow increases with the tuning parameter as well. Our results not only construct an acoustic black hole in regular black hole spacetime, but may also provide potential applications in future observations of astrophysical black holes. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) On the possibility of emergent light cones from relational shape dynamics https://arxiv.org/abs/2602.23853 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.23853v1 Announce Type: cross Abstract: We show that a universal propagation scale can emerge from purely relational, scale-invariant $N$-body dynamics formulated on shape space, i.e. the space of configurations modulo translations, rotations, and dilatations. Although pure shape dynamics treats only unparametrized curves as fundamental, we adopt an affine parametrization as a gauge choice to perform a perturbative analysis, with all physically meaningful results expressed in parametrization-independent terms. Linear perturbations around central configurations satisfy second-order equations on shape space whose high-frequency spectrum defines a dimensionless constant $c_{\mathrm{rel}}$. Under general conditions of reparametrization invariance, spectral universality, and strict hyperbolicity, $c_{\mathrm{rel}}$ functions as an emergent light-cone velocity, endowing the product space $\mathbb{R} \times \mathcal{S}$ with an effective Lorentzian structure. These results suggest that causal structure and a maximal signal speed may arise dynamically from the geometry and spectral properties of relational configuration space, providing a novel perspective on the origin of relativistic kinematics. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Dynamics of spinning particles in pp-wave spacetimes https://arxiv.org/abs/2602.24267 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2602.24267v1 Announce Type: cross Abstract: In this work, we study the dynamics of a spinning particle in pp-waves spacetimes; in particular, plane gravitational waves and impulsive shockwaves. W pay special attention to analytical considerations; this is possible due to an appropriate choice of the spin supplementary condition, various Hamiltonian formalisms (including a non-minimal one) and constants of motion associated with conformal fields. Based on these results, we establish a relation between the motions of a spinning particle in pp-waves and electromagnetic fields suggested by a gauge-gravity duality. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Curvature divergences in 5d $\mathcal{N} = 1$ supergravity https://arxiv.org/abs/2505.05558 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2505.05558v2 Announce Type: replace Abstract: We study the scalar curvature $R$ of the vector moduli space of 5d $\mathcal{N}=1$ supergravities, obtained by compactifying M-theory on a Calabi--Yau three-fold. We find that $R$ can only diverge at points where some gauge interactions go to infinite coupling in Planck units and become SCFTs or LSTs decoupled from gravity and other vector multiplets. For 5d SCFTs of rank $r\leq 2$ divergences occur if, additionally, the SCFT still couples to the vevs of such vector multiplets, so that along its Coulomb branch its gauge kinetic matrix and/or string tensions depend on some non-dynamical parameters. If the strong coupling singularity is better understood as a 6d $(1,0)$ SCFT, as in some decompactification limits, then divergences in $R$ arise when the SCFT is endowed with a non-Abelian gauge group. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Linear Resistivity from Spatially Random Interactions and the Uniqueness of Yukawa Coupling https://arxiv.org/abs/2507.09442 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2507.09442v5 Announce Type: replace Abstract: Recent studies have shown that a spatially random Yukawa-type interaction between a Fermi surface and critical bosons can produce linear-in-temperature resistivity, the defining signature of strange metals. In this article, we systematically classify all scalar couplings of the form $(\psi^{\dagger}\psi)^n\phi^m$ in arbitrary dimensions to identify possible candidates for strange-metal behaviour within this disordered framework. We find that only spatially random Yukawa-type interaction in $(2+1)$ dimensions can yield linear resistivity. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Holographic QCD Matter: Chiral Soliton Lattices in Strong Magnetic Field https://arxiv.org/abs/2507.16897 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2507.16897v3 Announce Type: replace Abstract: We investigate the chiral soliton lattice (CSL) in the framework of holographic QCD in magnetic field. Under appropriate boundary conditions for the gauge field and the quark mass deformation, we demonstrate that the ground state in the gravitational dual of QCD is given by the CSL in the background magnetic field and the baryon number density. In the presence of the background magnetic field, we show that the CSL is interpreted as a uniformly distributed D4-branes in the holographic setup, where the chiral soliton is identified with a non-self-dual instanton vortex or a center vortex in the five dimensional bulk gauge theory. While the baryon numbers are given to chiral solitons as well as Skyrmions due to the different terms in the Wess-Zumino-Witten (WZW) term in the chiral perturbation theory, these baryon numbers with different origins are unified in terms of the instanton charge density in five dimensions. With bulk analysis of the WZW term, we find that the pion decay constant becomes dependent on the magnetic field. For the massless pion case, we obtain an analytical form that is in qualitative agreement with lattice QCD results for strong magnetic fields. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Explorations of Universality in the Entropy and Hawking Radiation of Non-Extremal Kerr AdS$_4$ Black Holes https://arxiv.org/abs/2508.05322 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2508.05322v2 Announce Type: replace Abstract: We comprehensively discuss various microscopic approaches to the Bekenstein-Hawking entropy for rotating, electrically charged, asymptotically AdS$_4$ non-extremal black holes in gauged supergravity. We apply the covariant phase space formalism to the near-horizon region to obtain a Cardy-formula-based microscopic explanation for the entropy, consistent with the Kerr/CFT correspondence. From the dual boundary CFT point of view, we estimate the free partition function in the matrix model approximation in the high-temperature regime and find qualitative agreement with the supergravity answer. All these different approaches match in the appropriate limits and support the universality of AdS black hole entropy even at high temperatures, far away from extremality. Prompted by the consistency of the results of statistical explanations for the AdS$_4$ black hole entropy, we discuss aspects of the rate of Hawking radiation at high temperatures from the CFT$_2$ perspective and found it to be universally proportional to the horizon area. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Modified Unruh Thermodynamics in Emergent Gravity: Finite Heat Capacity and R\'enyi Entropy https://arxiv.org/abs/2509.03470 Mon, 02 Mar 2026 00:00:00 -0500 arXiv:2509.03470v2 Announce Type: replace Abstract: We show that Jacobson's thermodynamic derivation of Einstein's equations remains valid when local Rindler horizons are treated as finite heat-capacity systems, resolving the unphysical infinite-bath assumption of standard Unruh thermodynamics. The resulting entropy takes the form of R\'enyi entropy with nonextensivity parameter $\lambda\sim C^{-1}$, or equivalently, a new "Einstein entropy" that exactly preserves the Einstein equations for all heat capacities. In both cases, the Unruh temperature is modified as \begin{equation*} T_\text{mod}=\frac{\hbar\kappa}{2\pi}\left(1+\frac{S}{C}\right), \end{equation*} establishing a universal link between finite-capacity thermodynamics and nonextensive entropy. We further obtain a corrected scalar Einstein equation with an upper bound on horizon energy flux, pointing to testable signatures in heavy-ion collisions, accelerator spin polarization, and analog gravity experiments. These results reinforce the robustness of the emergent-gravity paradigm and connect spacetime dynamics to generalized entropies of quantum information theory. High_Energy_Physics/hep-th_(High_Energy_Physics_-_Theory) Real-Time Stream Compaction for Sparse Machine Learning on FPGAs https://arxiv.org/abs/2602.23281 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.23281v1 Announce Type: new Abstract: Machine learning algorithms are being used more frequently in the first-level triggers in collider experiments, with Graph Neural Networks pushing the hardware requirements of FPGA-based triggers beyond the current state of the art. To meet the stringent demands of high-throughput and low-latency environments, we propose a concept for latency-optimized preprocessing of sparse sensor data, enabling efficient GNN hardware acceleration by removing dynamic input sparsity. Our approach rearranges data coming from a large number of First-In-First-Out interfaces, typically sensor frontends, to a smaller number of FIFO interfaces connected to a machine learning hardware accelerator. In order to achieve high throughput while minimizing the hardware utilization, we developed a hierarchical sparsity compression pipeline optimized for FPGAs. We implemented our concept in the Chisel design language as an open-source hardware generator. For demonstration, we implemented one configuration of our module as preprocessing stage in a GNN-based first-level trigger for the Electromagnetic Calorimeter inside the Belle II detector. Additionally we evaluate latency, throughput, resource utilization, and scalability for a wide range of parameters, to enable broader use for other large scale scientific experiments. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Detector-level assessment of alternative target nuclei for CEvNS experiments under realistic experimental conditions https://arxiv.org/abs/2602.22234 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22234v1 Announce Type: cross Abstract: Coherent Elastic Neutrino-Nucleus Scattering (CEvNS) provides a sensitive probe of neutrino interactions at low momentum transfer, but its experimental observation is strongly constrained by detector-related effects such as energy threshold, resolution, noise, and event-selection criteria. In this work, we perform a detector-level assessment of CEvNS nuclear recoil observability under realistic experimental conditions, with particular emphasis on the role of detector response in shaping measurable recoil spectra. Using detailed Geant4-based simulations, CEvNS interactions are modeled for a set of alternative target nuclei spanning light to intermediate mass ranges. The true nuclear recoil energy distributions are propagated through a simplified yet realistic detector-response chain incorporating energy smearing, noise-induced fluctuations, threshold cuts, and veto-based event selection. We present a systematic analysis of recoil energy spectra before and after detector effects, response matrices linking true and reconstructed energies, and energy-dependent selection efficiencies. The results demonstrate that detector response effects significantly modify the observable CEvNS signal, particularly in the near-threshold region where most recoil events are concentrated. Differences in efficiency turn-on behavior and reconstructed energy distributions highlight the target-nucleus dependence of CEvNS observability under identical detector conditions. Rather than focusing on absolute event-rate predictions, this study emphasizes the relative impact of detector effects on signal accessibility and target performance. The presented framework provides a consistent methodology for evaluating and comparing prospective CEvNS target materials at the detector level, offering practical guidance for future low-threshold CEvNS experiments and detector design optimization. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) NASDUCK': Laboratory Limits on Ultralight Dark-Photon Dark Matter with Null-Axis Magnetometry https://arxiv.org/abs/2602.22308 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22308v1 Announce Type: cross Abstract: The dark photon is a well-motivated ultralight dark-matter candidate that may couple to the Standard Model through kinetic mixing. We search for dark-photon dark matter in the mass range $m_{A'}c^2 = 4\times10^{-12}$-$2\times10^{-9}\,\mathrm{eV}$ (1-500 kHz) using a three-axis magnetometer inside a large conductive shielded room. We set new laboratory limits on the kinetic-mixing parameter $\epsilon$, improving upon previous laboratory bounds by up to three orders of magnitude. Our search exploits a geometry-defined null response along one axis as a noise reference; a subtraction procedure reduces the noise floor and improves sensitivity. These results establish the strongest laboratory constraints in this mass range and illustrate how null-axis magnetometry can broaden terrestrial searches for ultralight vector dark matter. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) One Sum To Rule Them All: A Second Order Master Rate Sum Rule for Charm Decays https://arxiv.org/abs/2602.22320 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22320v1 Announce Type: cross Abstract: We show that within the Standard Model any system of hadronic weak charm decays related by $U$-spin satisfies the following rate sum rule: (sum of CF and DCS CKM-free rates) divided by (sum of SCS CKM-free rates) = 1, which holds up to second order in $U$-spin breaking. We test this sum rule against available data and find that it is well satisfied in all cases. For systems in which some decay rates have not yet been measured, we use this sum rule to predict the missing rates. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Robust Calibration of Non-Perturbative Models with History Matching https://arxiv.org/abs/2602.22324 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22324v1 Announce Type: cross Abstract: We apply, for the first time, Bayes Linear Emulation and History Matching to the calibration of non-perturbative models in Monte Carlo event generators. In contrast to the usual approach of "Monte Carlo tuning", History Matching does not result in best-fit plus ellipsoidal parameter uncertainty estimates but instead identifies all parameter space regions that are consistent with data. This approach leads to a systematic and robust quantification of parametric uncertainties in the models, especially in those challenging cases where different, possibly disjoint, regions of parameter space deliver similar results, which are usually not properly treated with current methodology. We highlight the power of this method with the hadronisation models available through Sherpa: the built-in cluster fragmentation Ahadic and string fragmentation through an interface to Pythia. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Flavorful Lepton Number Violation at the EIC https://arxiv.org/abs/2602.22355 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22355v1 Announce Type: cross Abstract: We explore the prospects of detecting flavorful lepton number violation at the Electron-Ion Collider (EIC) through resonant production of heavy neutral leptons (HNLs), resulting in $e^- p \to \ell^+_\alpha + k\, j+X$, where $\alpha \in \{e, \mu, \tau \}$ and $k$ denotes the number of jets. We work in the $\nu$SMEFT framework of the Standard Model Effective Field Theory augmented with $n$ singlet HNLs, one of which is in the mass range $10-100$~GeV, within kinematic reach of the EIC. To explore the EIC sensitivity, we focus on the HNL production mechanism induced by mixing with light neutrinos. We study kinematic distributions for signal and backgrounds, including hadronization and detector effects, and suggest a set of cuts to minimize backgrounds. In the mass range considered, we find that the EIC with muon detection capabilities and an integrated luminosity of $100~\mathrm{fb}^{-1}$ can reach sensitivities comparable to the strongest direct (LHC) and indirect constraints, and is especially relevant in the $\nu$SMEFT framework beyond dimension four. Our study motivates further assessment of muon detection capabilities at the EIC and $\tau$ hadronic reconstruction, as well as a more general theoretical analysis involving production mechanisms mediated by higher-dimensional operators in the effective theory. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Optimization-based Unfolding in High-Energy Physics https://arxiv.org/abs/2602.22776 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22776v1 Announce Type: cross Abstract: In High-Energy Physics, unfolding is the process of reconstructing true distributions of physical observables from detector-distorted measurements. Starting from its reformulation as a regularized quadratic optimization, we develop a framework to tackle this problem using both classical and quantum-compatible methods. In particular, we derive a Quadratic Unconstrained Binary Optimization (QUBO) representation of the unfolding objective, allowing direct implementation on quantum annealing and hybrid quantum-classical solvers. The proposed approach is implemented in QUnfold, an open-source Python package integrating classical mixed-integer solvers and D-Wave's hybrid quantum solver. We benchmark the method against widely used unfolding techniques in RooUnfold, including response Matrix Inversion, Iterative Bayesian Unfolding, and Singular Value Decomposition unfolding, using synthetic dataset with controlled distortion effects. Our results demonstrate that the optimization-based approach achieves competitive reconstruction accuracy across multiple distributions while naturally accommodating regularization within the objective function. This work establishes a unified optimization perspective on unfolding and provides a practical pathway for exploring quantum-enhanced methods in experimental HEP data analysis. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) First measurement of the strong interaction scattering parameters for the $\mathbf{K^-d}$ and $\mathbf{K^+d}$ systems https://arxiv.org/abs/2602.22833 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22833v1 Announce Type: cross Abstract: Charged kaon--deuteron interactions offer a sensitive probe of the strangeness sector of QCD at low energy, particularly through their scattering parameters. Despite available theoretical predictions, experimental constraints remain absent, particularly for the $\rm K^{-}d$ system. The first measurement of femtoscopic correlation functions for $\rm K^{-}d \oplus K^{+}\overline{d}$ and $\rm K^{+}d \oplus K^{-}\overline{d}$ particle pairs in Pb--Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV recorded by ALICE at the LHC is presented. Correlation functions for both systems are analyzed in three centrality classes and fitted using the Lednick\'y--Lyuboshitz model to extract the source size and strong interaction scattering lengths. The $\rm K^{-}d$ scattering length is found to be $\Re f_0 = -1.44 \pm 0.15\text{ (stat.)}^{+0.10}_{-0.10}$ (syst.) fm and $\Im f_0 = 1.34 \pm 0.33$ (stat.)$^{+0.21}_{-0.15}$ (syst.) fm, while for $\rm K^{+}d$ the value $\Re f_0 = -0.68 \pm 0.16$ (stat.)$^{+0.09}_{-0.09}$ (syst.) fm is obtained. These results provide the first constraints on the $\rm K^{\pm} d$ interaction modeling at low energy, delivering a long-awaited experimental benchmark for testing chiral QCD dynamics. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Testing beyond the Standard Model scenarios in next-generation long-baseline neutrino oscillation experiments https://arxiv.org/abs/2602.22849 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22849v1 Announce Type: cross Abstract: In this thesis, we assess the sensitivity of next-generation long-baseline neutrino oscillation experiments, DUNE, T2HK, and T2HKK, to three popular beyond the Standard Model (BSM) scenarios. Within the three BSM studies, we examine: (i) long-range neutrino-matter interactions induced by flavor-dependent, anomaly-free gauged baryon-lepton symmetries mediated by ultra-light vector boson, showing that DUNE and T2HK can constrain, discover, and in some favorable cases distinguish among different symmetries; (ii) Lorentz invariance violation (LIV), where we derive analytical dependencies of CPT-conserving and CPT-violating LIV parameters on baseline and energy, highlighting the superior reach of DUNE in probing all the LIV parameters, in contrast to T2HK, which is essentially blind to the CPT-conserving LIV parameters; and (iii) active-sterile oscillations over a broad range of $\Delta m^2_{41}$, where we derive sensitivity to CP phases for benchmark choices of $\Delta m^2_{41}$ and establish exclusion limits, emphasizing the role of near detectors. Together, these studies show that future long-baseline facilities not only resolve the neutrino mass ordering, value of $\delta_{\rm CP}$, and $\theta_{23}$ octant, but also provide powerful probes of BSM physics. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Bottom-charmed meson states in inverse problem of QCD https://arxiv.org/abs/2602.22872 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22872v1 Announce Type: cross Abstract: We present a comprehensive analysis of the bottom-charmed ($B_c$) meson spectrum within the inverse matrix QCD sum rules formalism. In this framework, conventional QCD sum rules are recast as an inverse problem, allowing for the direct reconstruction of hadronic spectral densities from first principles without invoking phenomenological continuum parametrizations or quark-hadron duality assumptions. We compute the masses and decay constants of conventional $B_c$ mesons with quantum numbers $J^P = 0^-$, $1^-$, $0^+$, and $1^+$. The obtained results are in close agreement with available experimental measurements and are consistent with predictions from various theoretical and phenomenological approaches. The inverse matrix formulation exhibits improved numerical stability and reduced systematic uncertainties relative to standard implementations, highlighting its suitability for precision spectroscopy of heavy quarkonium systems. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) NNLO QCD corrections to hadron production in DIS at finite transverse momentum https://arxiv.org/abs/2602.22972 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22972v1 Announce Type: cross Abstract: We present the first complete calculation of hadron production in deep-inelastic scattering (DIS) at finite transverse momentum to next-to-next-to-leading order (NNLO) in perturbative QCD. To overcome the long-standing challenge of infrared divergences in semi-inclusive processes with identified final state hadrons at finite transverse momentum, we implement the recently developed $q_T$-subtraction framework based on the recoil-free jet definition. By utilizing the winner-take-all recombination scheme, we achieve a consistent factorization for hadron-jet associated production, enabling the inclusion of $\mathcal{O}(\alpha_s^3)$ corrections. Our results demonstrate a significantly improved stabilization of the perturbative expansion and a reduction in scale uncertainties compared to previous next-to-leading order predictions. We find that the NNLO corrections are essential for a robust description of high precision multiplicity data from the ZEUS collaborations. This work provides a high precision theoretical foundation for the upcoming Electron-Ion Collider era and establishes a new benchmark for the exploration of the nucleon's three-dimensional structure. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Charge collection parameterization of MALTA2, a depleted monolithic active pixel sensor https://arxiv.org/abs/2602.23139 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.23139v1 Announce Type: cross Abstract: A fast simulation method is presented for a depleted monolithic active pixel sensor, which uses a data driven parameterization of the charge collection and propagation. This approach provides an efficient alternative to TCAD simulations, particularly for sensors whose proprietary process details - such as doping profiles or implant geometries - are unavailable. Data was obtained with a MALTA2 sensor fabricated in a 180 nm CMOS imaging technology on 30 {\mu}m epitaxial silicon using the MALTA beam telescope at CERN SPS. The model reproduces the measured inpixel efficiency with high accuracy and enables a realistic yet computationally lightweight analog pixel simulation. This method will be further employed in optimizing the digital sensor design for applications in high-rate particle tracking and high-granularity calorimetry. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Design and Development of Portable RPC-Based Cosmic Muon Tracker https://arxiv.org/abs/2503.01764 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2503.01764v3 Announce Type: replace Abstract: Primary cosmic rays when interact with our atmosphere, produce a cascade of lighter secondary particles namely pion, kaon, neutrons, muons, electrons, positrons and neutrinos. Muons are one of the most abundant and easily detectable particles at the ground surface using a large variety of particle detectors. Resistive Plate Chambers (RPCs) of 2m x 2m in dimension were developed to be used in large scale as the active detector elements in the Iron Calorimeter (ICAL) which was planned to be built by the India-based Neutrino Observatory (INO). As a spin-off of this work, a portable stack of eight, one square foot RPC detectors is developed named as Cosmic Muon Tracker (CMT). It could be used to conduct small-scale particle detector experiments as well as training Students. We will discuss design, integration, characterisation and some of the applications of this detector in this paper. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Cryogenics and purification systems of the ICARUS T600 detector installation at Fermilab https://arxiv.org/abs/2509.18392 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2509.18392v4 Announce Type: replace Abstract: This paper describes the cryogenic and purification systems of the ICARUS T600 detector in its present implementation at the Fermi National Laboratory, Illinois, USA. The ICARUS T600 detector is made of four large Time Projection Chambers, installed in two separate containers of about 275 m3 each. The detector uses liquid argon both as target and as active media. For the correct operation of the detector, the liquid argon must be kept in very stable thermal conditions and the contamination of electronegative impurities must be consistently kept at the level of small fractions of parts per billion. The detector was previously operated in Italy, at the INFN Gran Sasso Underground laboratory, in a 3 year duration run on the CERN to LNGS Long Baseline Neutrino Beam. For its operation on the Booster and NuMI neutrino beams, at Fermilab, for the search of sterile neutrinos and measurements of neutrino-argon cross sections, the detector was moved from Gran Sasso to CERN for the upgrades required for operation at shallow depth with high intensity neutrino beams. The liquid argon containers, the thermal insulation and all the cryogenic equipment, have been completely re-designed and rebuild, following the schemes of the previous installation in Gran Sasso. The detector and all the equipment have been transported to Fermilab, where they have been installed, tested and recently put into operation. The work described in this paper has been conducted as a joint responsibility of CERN and Fermilab with the supervision provided by the Icarus Collaboration. Design, installation, testing, commissioning and operation is the result of a common effort of CERN, Fermilab and INFN Groups. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Experimental study of the reaction $\Xi^{0}n\rightarrow\Lambda\Lambda X$ using $\Xi^{0}$-nucleus scattering https://arxiv.org/abs/2512.04701 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2512.04701v2 Announce Type: replace Abstract: Using $(10087\pm44)\times10^{6}$$J/\psi$ events collected with the BESIII detector operating at the BEPCII storage ring in $2009$, $2012$, $2018$, and $2019$, we perform a search for the reaction $\Xi^0n\rightarrow\Lambda\Lambda X$, where $X$ denotes any additional final particles. Given the highly suppressed phase space for producing extra pions, the $X$ consists of either nothing or a photon, corresponding to the processes $\Xi^0 n \rightarrow \Lambda\Lambda$ and $\Xi^{0}n\rightarrow\Lambda\Sigma^0\rightarrow\Lambda\Lambda\gamma$. The $\Xi^0$ comes from the decay of $J/\psi\rightarrow\Xi^0\bar{\Xi}^0$, while the neutron originates from material of the beam pipe. A signal is observed for the first time with a statistical significance of 6.4$\sigma$. The cross section for the reaction $\Xi^0+{^9\rm{Be}}\rightarrow\Lambda+\Lambda+X$ is measured to be $(43.6\pm10.5_{\text{stat}}\pm11.1_{\text{syst}})$ mb at $P_{\Xi^0}\approx0.818$ GeV/$c$, where the first uncertainty is statistical and the second systematic. No significant $H$-dibaryon signal is observed in the $\Lambda\Lambda$ final state. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) Binned and Unbinned Transverse Single Spin Asymmetry Extraction, including Background Subtraction and Unfolding https://arxiv.org/abs/2602.02325 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.02325v2 Announce Type: replace Abstract: The determination of transverse single-spin asymmetries in experiments involving polarized targets and/or beams may encounter challenges when (1) the magnitude of the polarization varies greatly with time, (2) the polarization magnitude is not the same for each spin state, (3) different integrated luminosities occur for different spin states or different target materials, and/or (4) some kinematic variables require unfolding; these are just a few examples. We present general methods of determining the asymmetry based on both binned analysis and unbinned maximum likelihood optimization, incorporating the unfolding of kinematic variables that are smeared by detector effects, and also including the possibility of background subtraction. High_Energy_Physics/hep-ex_(High_Energy_Physics_-_Experiment) The hadronic tensor from four-point functions on the lattice https://arxiv.org/abs/2602.22379 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22379v1 Announce Type: new Abstract: The hadronic tensor is the central non-perturbative object in the calculation of the cross section of lepton-hadron interactions like neutrino-nucleon scattering. It is usually parameterized in terms of structure functions, which encode all necessary information for all kinematic regions. Moreover, the structure functions can be factorized in terms of parton distribution functions (PDFs) and contains information on hadron resonances. On the lattice, we can calculate the corresponding matrix element of two quark-bilinear currents with a relative Euclidean time separation. The reconstruction of the hadronic tensor in Minkowski space requires appropriate dealing with the corresponding inverse problem. In our current work, we extend previous calculations on the nucleon by considering a much larger range of momentum transfers, which is inevitable in the context of structure functions. This can be achieved by using stochastic sources, which allows us to calculate the required four-point functions in a broad kinematic region. We employ a clover fermion ensemble at pion mass $m_\pi = 223~\mathrm{MeV}$ and lattice spacing $a=0.085~\mathrm{fm}$. In these proceedings, we will give an overview of our simulation and present some first preliminary results. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Confined and Deconfined Phases of Qubit Regularized Lattice Gauge Theories https://arxiv.org/abs/2602.22515 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22515v1 Announce Type: new Abstract: We construct simple qubit-regularized Hamiltonian lattice gauge theories formulated in the monomer--dimer--tensor-network (MDTN) basis that are free of sign problems in the pure gauge sector. These models naturally realize both confined and deconfined phases. Using classical Monte Carlo methods, we investigate the associated finite-temperature phase transitions and show that they exhibit the expected universality classes of conventional SU(N) lattice gauge theories in various spacetime dimensions. Furthermore, we argue that second-order quantum phase transitions separating the confined and deconfined phases are likely to exist. Such critical points would provide a nonperturbative route to defining continuum limits of qubit-regularized gauge theories, potentially allowing Yang--Mills theory and related continuum gauge theories to emerge from finite-dimensional lattice constructions. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Form factors of the $\rho$ meson from effective field theory and the lattice https://arxiv.org/abs/2602.23044 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.23044v1 Announce Type: new Abstract: The calculation of resonance form factors in effective field theory as well as on the lattice is a highly challenging task. In a recent paper, we proposed a novel method based on the introduction of a background field and the Feynman-Hellmann theorem to address the problem, and applied it to a toy model. In the present work we use this method for the electromagnetic form factors of the $\rho$-meson. By matching the results to Chiral Perturbation Theory, we provide a first, crude estimate of all three form factors of the $\rho$-meson within the effective field theory. Contact contributions to these form factors turn out to be substantial. A procedure for lattice calculations is outlined, paving the way for an ab initio approach to the problem. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Non-perturbative renormalization of the energy momentum tensor in the 2d O(3) nonlinear sigma model https://arxiv.org/abs/2602.23078 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.23078v1 Announce Type: new Abstract: The two-dimensional O(3) nonlinear sigma model is a well known toy model for studying non-perturbative phenomena in quantum field theory. A central challenge is the renormalization of the energy-momentum tensor, which is complicated by the nonlinear realization of the $O(3)$ symmetry leading to non-trivial operator mixing patterns, and by large discretization artifacts affecting the determination of renormalization constants. We present results for the renormalization constants in the non-singlet sector, employing a modified lattice action with shifted boundary conditions and defining the renormalized coupling through the gradient flow. While we obtain a precise determination of the relative mixing constant $z_T$, the overall normalization $Z_T$ remains inaccessible due to large discretization artifacts. We discuss the origins of these difficulties and outline possible paths forward. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Spatially inhomogeneous confinement-deconfinement phase transition in rotating QGP https://arxiv.org/abs/2602.23094 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.23094v1 Announce Type: new Abstract: Using first-principles numerical simulations, we find a new spatially inhomogeneous phase in a rotating gluon plasma. This mixed phase simultaneously contains regions of both confining and deconfining states in thermal equilibrium, separated by a spatial transition. The position of the boundary between the two phases is determined by the local critical temperature. We calculate the critical temperature of the local transition as a function of angular velocity and radius for a full (imaginary) rotating system and within a local thermalization approximation, and find an excellent agreement between these approaches. An analytic continuation of the results to the domain of real angular frequencies indicates that the confinement phase localizes at the periphery of the rotating system and the deconfinement phase appears closer to the rotation axis. We argue that the anisotropy of the gluon action in the curved co-rotating background can quantitatively explain the remarkable property that the spatial structure of this inhomogeneous phase disobeys the picture based on a straightforward implementation of the Tolman-Ehrenfest law. We also perform the first lattice simulation of rotating $N_f=2$ QCD which confirms that a similar picture is expected for theory with dynamical quarks. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Universal and non-universal finite-volume effects in the vicinity of chiral phase transition in (2+1)-flavor QCD https://arxiv.org/abs/2602.23118 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.23118v1 Announce Type: new Abstract: In this proceeding, we discuss the finite-size scaling analysis of the order parameter related to the chiral phase transition in QCD with two massless quarks. We use data obtained in lattice QCD calculations performed with highly improved staggered quarks (HISQ) for a range of light quark masses, $1/240 \leq m_\ell/m_s \leq 1/27$ for different spatial volumes ($N_\sigma$) on Euclidean lattices with temporal extent $N_\tau=8$, satisfying $3\,N_\tau \leq N_\sigma \leq 10\,N_\tau$. We observe that infinite volume extrapolated data for the order parameter agree reasonably well with the expected $O(2)$ scaling behavior even for physical ratios of the light-to-strange quark mass ratio. We quantify deviations from asymptotic scaling and perform a detailed analysis of the influence of finite-size effects in terms of temperature and quark masses at a fixed lattice cutoff. This is crucial for improving the reliability of the infinite-volume extrapolated estimate of the chiral order parameter and for a more precise determination of chiral phase transition temperature from direct Lattice QCD simulations. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Scaling and Luescher Term in a non-Abelian (2+1)d SU$(2)$ Quantum Link Model https://arxiv.org/abs/2602.23213 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.23213v1 Announce Type: new Abstract: We investigate a non-Abelian SU$(2)$ quantum link model in 2+1 dimensions on a hexagonal lattice using tensor network methods. We determine the static quark potential for a wide range of bare coupling values and find that the theory is confining. We also probe the existence of a Luescher term and find a clear signal, however, the value of the dimensionless constant $\gamma$ strongly deviates from the expected universal value $-\pi/24$ for almost all values of the coupling $g^2$ we investigated. The width of the strings scales logarithmically with the string length again for all $g^2$-values, providing evidence for a rough string, with no indication for a roughening transition. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Hadron spectroscopy and interactions https://arxiv.org/abs/2602.23244 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.23244v1 Announce Type: new Abstract: In recent years, lattice QCD calculations of hadron spectroscopy have concentrated on resonances and shallow bound states detected via poles in two- and three-hadron scattering amplitudes. Hadron interactions have therefore become a key focus. In these proceedings, I review the current state of the art and recent advances in methods for studying hadron interactions via finite-volume spectroscopy and finite-volume quantization conditions. I will also review recent spectroscopy studies and results presented at Lattice 2025, with a focus on charmed mesons, the doubly charmed tetraquark, and the doubly bottom tetraquark. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Quantum simulation of massive Thirring and Gross--Neveu models for arbitrary number of flavors https://arxiv.org/abs/2602.22313 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22313v1 Announce Type: cross Abstract: The study of fermionic quantum field theories is an important problem for realizing the standard model of particle physics on a quantum computer. As a step towards this goal, we consider the massive Thirring and Gross--Neveu models with arbitrary number of fermion flavors, $N_f$, discretized on a spatial one-dimensional lattice of size $L$ in the Hamiltonian formulation. We compute the gate complexity using the higher-order product formula and using block-encoding/qubitization and quantum singular value transformations in the limit of large $N_f$ and $L$. We also prepare the ground states of both models with excellent fidelity for system sizes up to 20 qubits with $N_f = 1,2,3,4$ using the adaptive-variational quantum imaginary time algorithm. In addition, we also classify the dynamical Lie algebras of these relativistic fermionic models and show that they belong to the same isomorphism class. Our work is a concrete step towards the quantum simulation of real-time dynamics of large $N_f$ fermionic quantum field theories models relevant for chiral symmetry breaking, understanding dimensional transmutation, and exploring the conformal window of field theories on near-term and early fault-tolerant quantum computers. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Fluctuation-Dissipation Relation for Hard Partons in a Gluonic Plasma https://arxiv.org/abs/2602.22338 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22338v1 Announce Type: cross Abstract: We derive a fluctuation dissipation relation connecting the drag and diffusion jet transport coefficients for an energetic light quark traversing a non-perturbative thermalized gluon plasma. The hard quark is taken to be close to on-shell, with an energy scale parametrically larger than the medium temperature. We introduce a general complex-valued function for each transport coefficient. Evaluating these in the deep Euclidean momentum region enables their expression in terms of local operators. Using contour-integration techniques, we relate these local operators, after vacuum subtraction, to the physical transport coefficients that arise along a branch cut, close to light-like dispersion. The derived relation relates the longitudinal drag coefficient to the longitudinal and transverse diffusion coefficients, a $4^{\rm th}$ order fluctuation, and the thermal gluon condensate. High_Energy_Physics/hep-lat_(High_Energy_Physics_-_Lattice) Dymnikova Black Hole Immersed in Perfect Fluid Dark Matter and a Cloud of Strings: Hawking Temperature, Dynamics and QPOs Analysis https://arxiv.org/abs/2602.22264 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22264v1 Announce Type: new Abstract: The Dymnikova black hole represents a regular spacetime solution interpolating between a de Sitter core and an asymptotically Schwarzschild geometry. In this work, we investigate a generalized Dymnikova black hole surrounded by perfect fluid dark matter (PFDM) and immersed in a cloud of strings (CS). We analyze how these additional matter sources modify the thermodynamic, optical, and dynamical properties of the spacetime. We derive the Hawking temperature and specific heat capacity and examine the thermal stability and phase structure of the black hole. The results reveal non-monotonic temperature behavior and parameter-dependent phase transitions. We further study photon dynamics, including the photon sphere and black hole shadow, and show that both PFDM and string cloud parameters significantly affect the shadow radius and strong-field structure. Additionally, we investigate the motion of massive test particles, circular orbits, and stability conditions. The corresponding effective potentials, specific energy, and angular momentum are analyzed. Finally, we explore quasi-periodic oscillations (QPOs) by computing the fundamental epicyclic frequencies and discuss how the model parameters encode observable astrophysical signatures. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Kasner Singularity of Black Holes in Einstein-scalar Gravity https://arxiv.org/abs/2602.22314 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22314v1 Announce Type: new Abstract: We study the spacelike Kasner singularity of spherically-symmetric, static and asymptotically flat black holes in Einstein gravity minimally coupled to a massless scalar with a suitable self-interacting scalar potential. We focus on how the asymptotic information such as the mass and scalar charge affect the properties of the Kasner singularity, including the Kasner exponents. We show how a nontrivial integration constant can be extracted from the near-singularity geometry and find a general pattern that this integration constant asymptotes to a linear combination of the mass and scalar charge at large mass limit. We also find that there may be a black hole upper bound on the maximum surviving time of a massive particle inside such a black hole before it falls into the Kasner singularity, and the Schwarzschild black hole saturate this bound. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Microscopic Origin of Bekenstein-Hawking Entropy in $(2+1)$ Gravity: A Thermo Field Dynamics Approach https://arxiv.org/abs/2602.22360 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22360v1 Announce Type: new Abstract: We compute the entanglement entropy of a real massive scalar field near a non-rotating BTZ black hole using Thermo Field Dynamics. Modeling the black hole as a collapsing dust shell in AdS3, we derive the shell trajectory R(t) as seen by a Fiducial Observer (FIDO). From the Hartle-Hawking and Killing-Boulware vacua, we obtain the Wightman function difference and compute energy density, revealing a sharply localized energy density just outside the horizon, consistent with the brick wall picture. A full thermodynamic analysis yields an entanglement entropy proportional to the horizon area, numerically matching the Bekenstein-Hawking entropy. All intermediate steps, including junction conditions, Kruskal extension, WKB modes, and UV regularization, are explicitly detailed. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) WKB-like approach to the Unruh temperature for arbitrary acceleration https://arxiv.org/abs/2602.22534 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22534v1 Announce Type: new Abstract: In this work we study the Unruh temperature as arising from tunneling through a barrier for an observer in flat Minkowski spacetime with arbitrary acceleration $a(t)$. For the defining case of constant acceleration $a(t) = a_0$, the Unruh temperature (W. Unruh, Phys. Rev. D 14, 870 (1976)) is given by $k_b\,T_U =\tfrac{\hbar\,a_0}{2\,\pi\,c}$. Extending the work of de Gill et al. (A. de Gill, D. Singleton, V. Akhmedova and T. Pilling, Am. J. Phys. 78, 685 (2010)) we generalize the gravitational WKB approach to derive the Unruh temperature for arbitrary acceleration. We show that the often employed Schwarzschild-like form of the flat metric is not appropriate for the WKB calculation with an arbitrary $a(t)$, and instead derive a generalized Unruh temperature for the generalized Rindler metric where $a_0\to a(t)$. We derive a generalization of the Rindler coordinates appropriate for arbitrary $a(t)$, and stress the importance of the role of the integrated acceleration $\chi(t) = \int^t dt'\,a(t')$, which can also act as a temporal coordinate. We explore several non-trivial examples of $a(t)$ and their generalized Unruh temperatures. We additionally develop an approximation to the Unruh temperature for small deviations away from constant acceleration by the standard approach of considering the negative frequency content of a purely positive frequency plane wave of an inertial observer, as measured by the co-moving arbitrarily accelerated observer. Lastly, we develop and explicit coordinate transformation between the arbitrarily accelerated observer and conformal coordinates, where the plane wave structure of the solutions of the wave equation is readily transparent, and analogous to the form for the inertial observer. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Quantum corrected thermodynamics and horizon quantization of the Reissner--Nordstr\"om black hole https://arxiv.org/abs/2602.22559 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22559v1 Announce Type: new Abstract: In this letter, we develop a unified semiclassical framework for the thermodynamics and quantization of the Reissner--Nordstr\"om (RN) black hole (BH) based on the Misner--Sharp--Hernandez (MSH) mass. Treating the quasi-local horizon energies as the relevant thermodynamic variables, we formulate a horizon-by-horizon first law and Smarr relation. Using a reduced phase-space quantization, we obtain a discrete MSH mass spectrum for both horizons, which reproduces the minimal entropy spacing. Quantum transitions between adjacent levels yield Planck-scale corrections to the Hawking temperatures and a universal logarithmic contribution to the entropy, consistent with independent approaches to quantum gravity. We encode these corrections into a quantum-deformed RN geometry via a simple multiplicative factor that preserves the classical horizon positions while reproducing the corrected surface gravities. The associated effective stress tensor behaves as a conserved vacuum-polarization source with characteristic $r^{-4}$ falloff and a small trace, providing a compact representation of semiclassical backreaction. The deformation slightly lowers both horizon temperatures, weakens the inner-horizon instability, and induces tiny shifts in photon-sphere and shadow observables for macroscopic BHs. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Lorentzian Vacuum Transitions in $f(R)$ gravity https://arxiv.org/abs/2602.22561 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22561v1 Announce Type: new Abstract: We study Lorentzian vacuum transition probabilities between two minima of a scalar field potential within the framework of $f(R)$ gravity. The analysis extends the previously considered WKB expansion of the Wheeler-DeWitt equation to modified gravity theories, up to second order. We apply the general method for homogeneous and isotropic FLRW universes, with zero and positive spatial curvature, for any $f(R)$ model. For the flat case we obtain analytic expressions for the transition probabilities for any model if we assume a constant Ricci scalar; this assumption has been considered in previous studies, in the Euclidean approach, from symmetry arguments. On the other hand, we also obtain explicit solutions without this assumption for power-law $f(R)=R^{1+n}$ models. Moreover, in the positive curvature scenario, we obtain that the assumption of a constant Ricci scalar is not consistent, but we are able to find analytical solutions in approximated regimes. In all cases we have found that the general behavior of the probabilities already found for Einstein Gravity is preserved, including the prediction of a non-singular initial state due to quantum corrections, even though the probabilities increase or decrease in a model dependent way. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Light propagation and gravitational lensing effects in charged Kalb-Ramond spacetime in nonlinear electrodynamics https://arxiv.org/abs/2602.22905 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22905v1 Announce Type: new Abstract: In this work, we theoretically investigate the deflection of light for strong- and weak-field regimes in the background of an electrically charged BH described in Kalb-Ramond gravity, which introduces the Lorentz symmetry violation parameter $l$, as well as the control of the degree of nonlinearity incorporated by electrodynamics through the parameter $\gamma$. We analytically constructed the expansion coefficients in both limits and used them as a basis to investigate gravitational lensing effects through observables, taking into account the variation of the parameters involved in the model, both for the canonical field and the phantom case. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Quantum Oppenheimer-Snyder Black Holes with a Cloud of Strings Surrounded by Perfect Fluid Dark Matter https://arxiv.org/abs/2602.22928 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22928v1 Announce Type: new Abstract: In this study, we examine quantum Oppenheimer-Snyder black holes (BHs) embedded within a cloud of strings and immersed in perfect fluid dark matter. Also, beginning with the underlying spacetime geometry, we determine how quantum corrections, string cloud contributions, and dark matter effects alter the geometrical structure and physical characteristics of the BH. Also, the optical behavior is investigated via a systematic analysis of the photon sphere and the associated BH shadow, emphasizing possible observational features capable of differentiating this configuration from classical models. We also analyze the motion of test particles, focusing on how surrounding matter components affect trajectories, stability conditions, and effective potentials. Scalar field perturbations are considered to investigate the BH response to external excitations and to extract information regarding its dynamical properties. In this case, the thermodynamic behavior of the system is studied, including the role of string clouds and dark matter in modifying BH thermodynamic quantities. Also, the obtained results present a unified description of the combined effects of quantum corrections, nonstandard matter sources, and BH physics, with potential relevance for both observational constraints and theoretical modeling of compact objects. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Testing the Weak Gravity Conjecture via Gravitational Lensing, Black Hole Shadows, and Barrow Thermodynamics in F(R)-Euler-Heisenberg (A)dS Black Holes https://arxiv.org/abs/2602.22930 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22930v1 Announce Type: new Abstract: We investigate the interplay of the Weak Gravity Conjecture (WGC) and the Weak Cosmic Censorship Conjecture (WCCC) in $F(R)$-Euler-Heisenberg black holes in Anti-de Sitter and de Sitter backgrounds. The solution is characterized by the electric charge $q$, the $F(R)$ deviation $f_{R_0}$, the Euler--Heisenberg coupling $\lambda$, and the constant scalar curvature $R_0$. We establish a universal entropy--extremality relation that provides thermodynamic evidence for the WGC independently of $f_{R_0}$ and $R_0$. Photon sphere analysis from both geodesic and topological perspectives confirms the simultaneous compatibility of the WGC and WCCC, with the Euler--Heisenberg coupling restoring photon spheres in the naked singularity regime. Gravitational lensing in the strong- and weak-deflection limits reveals that the photon sphere radius is independent of the cosmological background while the critical impact parameter nearly doubles in de Sitter. Black hole shadow images under isotropic accretion are constructed. Within the Barrow entropy framework, we uncover van der Waals-type phase transitions and analyze Joule-Thomson expansion, identifying the small black hole phase as the WGC-compatible thermodynamic regime accessible via isenthalpic cooling. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Charged scalar and Dirac perturbations on a global monopole Reissner-Nordstr\"om-de Sitter black hole: quasinormal modes and strong cosmic censorship https://arxiv.org/abs/2602.23083 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.23083v1 Announce Type: new Abstract: We study perturbations of charged scalar and Dirac fields around Reissner-Nordstr\"om-de Sitter black holes with a global monopole. To this end, we first derive the equations of motion for both fields on the aforementioned background; these equations are then reformulated uniformly into the Teukolsky equation. Since the Teukolsky equation in asymptotically de Sitter spacetimes can be mapped into the Heun equation, we are able to solve quasinormal spectra by employing the Heun function method, not only for photon sphere modes but also for de Sitter and near-extremal modes. We analyze the spectra of all three types for both fields and, in particular, ascertain the effects of the global monopole. In the near-extremal regime, we find that the presence of a global monopole, on the one hand, leaves the strong cosmic censorship conjecture unaffected for scalar perturbations, while on the other hand, it enhance the violation of strong cosmic censorship for Dirac perturbations. Furthermore, we identify that the impact of the global monopole on both the spectra and the strong cosmic censorship is achieved by a shift in the modified multipole number. Our work demonstrates that the Heun function method is an efficient and robust approach for exploring the interaction between asymptotically de Sitter black holes and perturbing fields. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Spherically Symmetric Gravity on a Graph I: Theoretical Foundations https://arxiv.org/abs/2602.23308 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.23308v1 Announce Type: new Abstract: This manuscript is the first in a series of instalments that investigate spherically symmetric solutions within the effective dynamics program of Loop Quantum Gravity. The choice of lattice is adapted such that it remains invariant under a set of symmetry transformations maximally mapping spherical symmetry to the discrete setting. The conditions for symmetry restriction of the dynamics are investigated and a subspace is identified to make computations feasible. Afterwards symplectic structure and scalar constraint are explicitly computed on this subspace. This lays the groundwork to target several particular solutions, such $k=1$ cosmology and black holes, which will serve as the subjects of forthcoming follow-up papers. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Black holes and bits: A simple path to Bekenstein-Hawking entropy https://arxiv.org/abs/2602.22245 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22245v1 Announce Type: cross Abstract: In the early 1970s, Jacob Bekenstein discovered that black holes have entropy, which became one of the greatest scientific revolutions of the second half of the 20th century. The objective of this paper is to present a simple derivation -- partly heuristic and partly geometric -- of the equation for the entropy of a black hole, which we now know as the Bekenstein-Hawking entropy. We will also briefly explore the physical implications of this equation and its relationship to the work of Stephen Hawking. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Gravitational decoherence and recoherence of a composite particle: the interplay between gravitons and a classical Newtonian potential https://arxiv.org/abs/2602.22517 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22517v1 Announce Type: cross Abstract: The fact that gravitational environments cannot be shielded (since gravity is universal) makes them of great theoretical interest to decoherence mechanisms and to the quantum-to-classical transition. While past results seemed to indicate that graviton-induced decoherence of spatial superpositions happens only for macroscopic systems, recently it was shown that this mechanism can be enhanced through the system's own dynamical internal structure. In this work, we extend this analysis by including the interaction with a classical Newtonian potential. We show that, although the graviton bath alone dominates the mechanism for short times compared to a timescale established by the size of the quantum spatial superposition, the interplay between the gravitons and the internal degrees of freedom of the system renders decoherence inevitable in the long-time limit, even for microscopic masses. We also show that this mechanism is slightly slowed down by the interplay with the classical Newtonian potential, which, for systems without dynamical internal degrees of freedom, can even lead to recoherence, at least in principle. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Effective Repulsive Action of Gravitational Quantum Superpositions Under Postselection https://arxiv.org/abs/2602.22715 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22715v1 Announce Type: cross Abstract: A classic feature of gravity is that it is an attractive force. If a source mass is prepared in a localized (classical- like) state, it will cause another probe mass to move towards it. Here we consider the situation in which a source mass is prepared in a quantum superposition of distinct spatial states while a probe mass interacts with it. Conditional on the detection of the source mass in a specific state, the probe mass will be found to move away from the source mass (repulsion). This signifies the quantum superposition of gravitational forces acting on the probe mass and thereby the fact that spacetime can exist in quantum superpositions. The technique used is the repulsive effect arising from an anomalous negative weak value. A potential experimental implementation with spin bearing nanocrystals is outlined. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology) Geodesic equation in noncommutative space: a field theory perspective https://arxiv.org/abs/2602.22726 Fri, 27 Feb 2026 00:00:00 -0500 arXiv:2602.22726v1 Announce Type: cross Abstract: We derive the geodesic equation for point particles propagating in Moyal-type noncommutative spacetimes using a field-theoretic approach based on the quasi-classical limit of the noncommutative Klein-Gordon equation. Starting from a twisted-geometric construction of the covariant Laplace-Beltrami operator, we obtain the noncommutative Hamilton-Jacobi equation and show that all noncommutative effects are absorbed into an effective, position-dependent mass function $M(x)$ appearing in an otherwise standard relativistic dispersion relation. The corresponding particle dynamics then acquires an additional term in the geodesic equation that takes the form of a fixed external force $F_{\text{NC}}^\mu = -\frac{1}{2} g^{\mu\nu}\partial_\nu M^2(x)$, sourced entirely by the quantum nature of spacetime. We compute this effective mass perturbatively up to fourth order in the noncommutativity parameter for a general metric, proving that all odd-order corrections vanish identically. For the specific case of an $(r-\theta)$ twist applied to spherically symmetric backgrounds, we obtain explicit expressions demonstrating that the leading correction to geodesic motion appears at $\Theta^2$ order and is proportional to the probe particle's mass, while massless particles remain unaffected. High_Energy_Physics/gr-qc_(General_Relativity_and_Quantum_Cosmology)