Wed·Jul 2, 2025Wednesday·July 2, 2025

1. 01*

   Entanglement, Trace Anomaly and Confinement in QCD

   Kiminad A. Mamo🇺🇸

   We formulate confinement in QCD as an entropic surface phenomenon. Quark and gluon quantum information is localized on a transverse entangling two-sphere of radius $R_{EE}$; at this radius the QCD vacuum -- partitioned by a hadron into interior and exterior regions -- reaches its maximal entanglement entropy. Lattice-QCD determinations of the scalar (trace) gravitational form factors fix both $R_{EE}$ and the transverse trace-anomaly density ${\rho }_h(R_{EE})$, yielding a parameter-free slope $c_h=8{\pi }^2{R}_{EE}^2{\rho }_h(R_{EE})$ and a mechanical entropy $S_{EE}(y)=c_{h}y$ that grows linearly with rapidity $y$. The entropy gradient ${\partial }_R{S}_{EE}$ changes sign at $R_{EE}$: it pushes colored degrees of freedom outward for $r<R_{EE}$ and pulls them inward for $r>R_{EE}$, thereby localizing them on the codimension-2 entangling two-sphere ${\Sigma }_{\perp }=S_{R_{EE}}^2$ (which, in the infinite-momentum frame, projects onto the transverse plane), the 'information wall'. This provides a high-energy (large-$y$) entropic confinement diagnostic that complements -- rather than replaces -- Wilson's area-law criterion, which probes long-distance dynamics near the rest frame ($y\to 0$). Imposing unitarity on an entropic ansatz for the amplitude yields $\sigma (s)\propto y^{\delta }$. World data favor $\delta =2$ for elastic $pp(p\bar{p})$ scattering and heavy-quark photoproduction, whereas $\varphi$ photoproduction favors a softer $\delta =0.387$. All extracted cross sections remain well below the Froissart--Martin bound. These results provide a confinement criterion quantified directly from non-perturbative QCD inputs, unifying the trace anomaly, entanglement entropy, and high-energy scattering within a single quantitative framework.

   hep-phhep-thnucl-thPRD(2025)·6 citations
2. 02*

   Discovering the Underlying Analytic Structure Within Standard Model Constants Using Artificial Intelligence

   S. V. Chekanov🇺🇸 · H. Kjellerstrand🇨🇴

   This paper presents a method for uncovering hidden analytic relationships among the fundamental parameters of the Standard Model (SM), a foundational theory in physics that describes the fundamental particles and their interactions, using symbolic regression and genetic programming. Using this approach, we identify the simplest analytic relationships connecting pairs of these constants and report several notable expressions obtained with relative precision better than 1%. These results may serve as valuable inputs for model builders and artificial intelligence methods aimed at uncovering hidden patterns among the SM constants, or potentially used as building blocks for a deeper underlying law that connects all parameters of the SM through a small set of fundamental constants.

   hep-phcs.AIphysics.data-anParticles(2025)·3 citations
3. 03*

   Anti-Electron Neutrinos at High-Energy Neutrino Experiments: Identification Strategies and Physics Potential

   Felix Kling🇩🇪 · Toni Mäkelä🇺🇸 · Josh McFayden🇬🇧

   Most existing and proposed high energy neutrino experiments have excellent muon charge identification capabilities, enabling the distinction of ${\nu }_{\mu }$ and ${\bar{\nu }}_{\mu }$ charged current interactions. In contrast, distinguishing electrons and positrons from ${\nu }_e$ and ${\bar{\nu }}_e$ interactions is typically impossible, as they quickly interact within the characteristically dense detector material and fail to reach the spectrometer. In this letter, we propose a compact and cost-effective plastic target, placed right before the spectrometer, to maximize the rate of electrons and positrons that reach the spectrometer before interacting. We demonstrate that, when installed at the FASER experiment, the Forward Physics Facility, or SHiP, this setup could enable the first separate measurement of ${\nu }_e$ and ${\bar{\nu }}_e$ cross sections at high energy. Additionally, this setup opens new opportunities to study forward particle production at collider neutrino experiments, such as constraining forward $\Lambda$ hyperon production, and, by reducing flux uncertainties, significantly improve limits on non-standard neutrino interactions in neutral currents.

   hep-phPRD(2026)·5 citations
4. 04*

   Earth-Scattering Induced Modulation in Low-Threshold Dark Matter Experiments

   Xavier Bertou🇫🇷 · Ansh Desai🇺🇸 · Timon Emken🇸🇪 · Rouven Essig🇺🇸 · Tomer Volansky🇮🇱 · Tien-Tien Yu🇺🇸

   Dark matter particles with sufficiently large interactions with ordinary matter can scatter in the Earth before reaching and scattering in a detector. This induces a modulation in the signal rate with a period of one sidereal day. We calculate this modulation for sub-GeV dark matter particles that interact either with a heavy or an ultralight dark-photon mediator and investigate the resulting signal in low-threshold detectors consisting of silicon, xenon, or argon targets. The scattering in the Earth is dominated by dark matter scatters off nuclei, while the signal in the detector is easiest to observe from dark matter scattering off electrons. We investigate the properties of the modulation signal and provide projections of the sensitivity of future experiments. We find that a search for a modulation signal can probe new regions of parameter space near the energy thresholds of current experiments, where the data are typically dominated by backgrounds.

   hep-phastro-ph.COhep-exJHEP(2025)·8 citations
5. 05*

   Searching for long-lived light neutralinos from $B$-meson decays with baryonic R-parity violation at Belle II

   Emilie Bertholet🇮🇱 · Claudio O. Dib🇨🇱 · Sara P. Gandelman🇮🇱 · Juan Carlos Helo🇨🇱 · Valery E. Lyubovitskij🇨🇱 · Minakshi Nayak🇮🇳 · Nicolás A. Neill🇨🇱 · Abner Soffer🇮🇱 · Zeren Simon Wang🇨🇳

   In a supersymmetry scenario with R-parity violation (RPV), neutralinos with GeV-scale mass, which are necessarily bino-like, are allowed by all constraints and can be produced in association with a baryon in $B$-meson decays via certain $\bar{U}\bar{D}\bar{D}$ operators. In this work, we investigate this scenario with two non-vanishing RPV couplings at the low-energy scale. With one RPV coupling governing the neutralino production rate and another determining its lifetime, this scenario can lead to observable signals with displaced-vertex signatures in the tracking volume of $B$-factories. To maximize the sensitivity to such signals, we develop a new partial-reconstruction technique that yields high efficiency and utilizes most of the decays of relatively heavy, long-lived particles, achieving much better sensitivity than standard full reconstruction. We consider potential background sources and devise selection criteria to suppress their event yields to very low levels. Using a parameterized model of the detector, we estimate in detail the displaced-vertex reconstruction efficiency as a function of neutralino lifetime and mass. For squark masses beyond the LHC limits, we calculate the signal sensitivity of Belle~II, showing that the experiment can probe the RPV couplings well beyond the present bounds, obtained from searches for dinucleon decays, baryon-antibaryon oscillations, and $B^{+}\to p+\text{missing}$.

   hep-phhep-exJHEP(2025)·3 citations
6. 06*

   Unified study of two-meson and axion-meson production from semileptonic tau decays within resonance chiral framework

   Jin Hao🇨🇳 · Chun-Gui Duan🇨🇳 · Zhi-Hui Guo🇨🇳

   We carry out the joint study of the semileptonic tau decays into the two-meson and axion-meson channels, viz. ${\tau }^{-}\to (P_1{P}_2{)}^{-}{\nu }_{\tau }$ and ${\tau }^{-}\to {\pi }^{-}(K^{-})a{\nu }_{\tau }$ within the framework of resonance chiral theory by including the model-independent axion-gluon-gluon interaction. By utilizing the ${\pi }^0$-$\eta$-${\eta }^{\prime }$-axion mixing matrix elements from recent studies, we calculate the pertinent two-pseudoscalar boson form factors. To simultaneously fit the experimental spectra measured in the Cabibbo allowed ${\tau }^{-}\to {\pi }^{-}{\pi }^0{\nu }_{\tau }$ process and also the Cabibbo suppressed ${\tau }^{-}\to (K_S{\pi }^{-},K^{-}\eta ){\nu }_{\tau }$ ones, we determine all the relevant hadron resonance parameters. Then we give predictions to the spectra and branching ratios for various channels, such as ${\tau }^{-}\to ({\pi }^{-}\eta ,{\pi }^{-}{\eta }^{\prime },K^{-}{\eta }^{\prime },{\pi }^{-}a,K^{-}a){\nu }_{\tau }$. We also calculate the forward-backward asymmetries for all the aforementioned channels. The interplay between the scalar and vector form factors for different observables is analyzed in detail. Our theoretical predictions supply useful guidance to the future tau experiments, such as those at Belle-II, Super Tau-Charm Facility and Tera-Z factory of Circular Electron-Positron Collider.

   hep-phFront.Phys.(Beijing)(2026)·2 citations
7. 07*

   Susceptibilities of rotating quark matter in Fourier-Bessel basis

   Mamiya Kawaguchi🇨🇳 · Kazuya Mameda🇯🇵

   We analyze various two-point correlation functions of fermionic bilinears in a rotating finite-size cylinder at finite temperatures, with a focus on susceptibility functions. Due to the noninvariance of radial translation, the susceptibility functions are constructed using the Dirac propagator in the Fourier-Bessel basis instead of the plane-wave basis. As a specific model to demonstrate the susceptibility functions in an interacting theory, we employ the two-flavor Nambu-Jona-Lasinio model. We show that the incompatibility between the mean-field analysis and the Fourier-Bessel basis is evaded under the local density approximation, and derive the resummation formulas of susceptibilities with the help of a Ward-Takahashi identity. The resulting formulation reveals the rotational effects on meson, baryon number, and topological susceptibilities, as well as the moment of inertia. Our results may serve a useful benchmark for future lattice QCD simulations in rotating frames.

   hep-phhep-latnucl-thJHEP(2025)·4 citations
8. 08*

   Photoinduced inclusive cross sections in hadronic collisions at the LHC

   Robert Gȩbarowski🇵🇱 · Agnieszka Łuszczak🇵🇱 · Marta Łuszczak🇵🇱 · Wolfgang Schäfer🇵🇱

   We discuss inclusive electromagnetic dissociation processes in proton--proton ($pp$) and proton--nucleus ($pA$) scattering at the LHC where one or both of the protons dissociate. These processes which involve the exchange of a virtual photon in the $t$--channel are calculable in terms of deep inelastic structure functions (virtual photoabsorption cross sections). For the $pA\to XA$ reaction there emerges the possibility of measuring the total photoabsorption cross section on the proton at very high energies.

   hep-phPLB(2025)·1 citation
9. 09*

   QCD phase transition at finite temperature and chemical potential with the non-extensive statistics

   Zhi-Ying Qin🇨🇳 · Jia-Hao Shi🇨🇳 · Jin-Peng Zhang🇨🇳 · Jian Cao🇨🇳 · Bo Feng🇨🇳 · Wen-Chao Zhang🇨🇳 · Hua Zheng🇨🇳 · Shi-Jun Mao🇨🇳

   The intrinsic fluctuations, memory effects and long-range color interactions in high energy nuclear collisions imply the presence of non-Markovian processes in the fireball evolution, which affects the thermalization process towards equilibrium and produces a non-extensive behavior. In order to investigate the non-equilibrium effect on the quantum chromodynamics (QCD) phase transition at finite temperature ($T$) and chemical potential ($\mu$), we apply a non-extensive correction to the equation of state in the parton (hadron resonance) gas at high (low) temperature and interpolate these two equation of states with a smooth crossover. The non-extensive statistics is characterized by a non-extensivity parameter $q$, which measures the degrees of deviation from the thermal equilibrium. It is found that the dimensionless thermodynamic quantities such as the entropy density, the pressure, the energy density, the specific heat at constant volume and the trace anomaly are sensitive to the deviation of $q$ from unity and they become large both in the hadronic and quark-gluon plasma phases with the increase of $q$. Moreover, this deviation leads to nontrivial corrections of the squared speed of sound ($(c_s^2{)}_q$) in the vicinity of the critical point ($T_c$) and at lower temperatures. Additionally, these thermodynamic quantities are sensitive to the deviation of $\mu$ from zero. With increasing $\mu$, they become enhanced in both phases. Specifically, for $(c_s^2{)}_q$, the value increases near $T_c$ but decreases at lower temperatures. Finally, we observe that our results with $q=1$ agree well with those from the Lattice QCD, the hadron resonance gas model, and the Thermal-Fist fit to the hadron yields in high energy nuclear collisions in the low temperature region up to $T\sim 150$ MeV.

   hep-phPRD(2025)·5 citations
10. 10*

    A Non-Inflationary Axion and ALP Misalignment Mechanism

    Robert Brandenberger (McGill University)🇨🇦

    Based on considerations of quantum gravity, global symmetries which lead to axions as pseudo Nambu-Goldstone bosons after low scale symmetry breaking cannot be exact at the Planck scale. Here, we show that Planck-suppressed terms which yield this symmetry breaking may provide a non-inflationary misalignment mechanism which can generate coherent oscillations of the axion and axion-like particle (ALP) fields at low temperatures.

    hep-phastro-ph.COgr-qchep-thPRD(2025)·12 citations
11. 11*

    Burgers equation for the bulk viscous pressure of quark matter

    José Luis Hernandez🇪🇸 · Cristina Manuel🇪🇸 · Saga Säppi🇪🇸 · Laura Tolos🇪🇸

    The dissipative properties of relativistic strongly interacting nuclear matter significantly influence the damping of stellar oscillations and density fluctuations during compact star mergers. In this work, we derive the evolution equation for the bulk viscous pressure in unpaired quark matter under small deviations from equilibrium. Our analysis reveals that it behaves like a two-component Burgers fluid. We identify four key transport coefficients -- two relaxation times and two bulk viscosity coefficients -- expressed in terms of equilibrium parameters and electroweak nonleptonic and semi-leptonic decay rates. The transport coefficients are evaluated for two distinct equations of state: one based on perturbative quantum chromodynamics and the other on a modified MIT bag model, valid in different density regimes. We also determine the temperature and density region where nonleptonic electroweak processes dominate the dissipation. Our formulation establishes a new way of describing bulk viscous effects in quark matter, applicable for numerical simulations of compact star mergers.

    hep-phgr-qcnucl-thPRD(2026)·7 citations
12. 12*

    Molecular states with bottom mesons and multistrange baryons systems

    Jing Song🇨🇳 · Yi-Yao Li🇨🇳 · Eulogio Oset🇪🇸

    We investigate molecular states formed by bottom mesons and multistrange baryons from both octet and decuplet flavor representations, using the local hidden gauge approach combined with coupled-channel Bethe-Salpeter equations. Focusing on strangeness sectors \(S = -1\) to \(-4\), we predict several bound states in the \(S=-1, I=1/2,~3/2\) and \(S=-2, I=0\) sectors. No bound states are found in other isospin channels, where the interaction is repulsive, nor in higher strangeness sectors. The binding energies are analyzed under different values of the cutoff regularization parameters, providing estimates of theoretical uncertainties. This study provides concrete predictions to support future experimental investigations and improve understanding of heavy-flavor multistrange exotic hadrons.

    hep-phEPJC(2025)·1 citation
13. 13*

    Interplay of prompt and non-prompt photons in photon-triggered jet observables

    Chathuranga Sirimanna🇺🇸 · Yasuki Tachibana🇯🇵 · Abhijit Majumder🇺🇸 · Aaron Angerami🇺🇸 · Ritu Arora🇺🇸 · Steffen Bass🇺🇸 · Yi Chen🇺🇸 · Ritoban Datta🇺🇸 · Lipei Du🇨🇦 · Raymond Ehlers🇺🇸 · Hannah Elfner🇩🇪 · Rainer J. Fries🇺🇸 and 40 other authors

    Prompt photons are important yet challenging to observe in relativistic heavy-ion collisions, as they are produced in the early stages and traverse almost the entire QGP medium without interaction. Experimental analyses typically employ isolation cuts, in the hope to identify prompt photons. Most theoretical studies consider only events with actual prompt photons, assuming no contribution from isolated non-prompt photons to reduce computational cost. For the first time, we present a study that compares simulation results generated using inclusive (bremsstrahlung) and prompt-photon events with multiple experimental observables for both $p-p$ and $Pb-Pb$ collisions at $5.02$ TeV. Simulations are carried out using the multi-stage JETSCAPE framework tuned to describe the quenching of jets and hadrons. Isolated non-prompt photons are generated in hard photon bremsstrahlung, where the photon is radiated at a sufficient angle to the jet. Several photon triggered jet and jet substructure observables show significant contributions from inclusive photons, yielding an improvement in comparison with experimental data. Novel photon triggered jet substructure observables are also expected to show new structures, yet to be detected in experiment. This effort examines the significance of isolated non-prompt photons using parameters tuned for a simultaneous description of the leading hadron and jet spectrum, and thus provides an independent verification of the multistage evolution framework.

    hep-phnucl-exnucl-thEPJ Web Conf.(2025)·0 citations
14. 14*

    Connecting $t$-channel Dark Matter Models to the Standard Model Effective Field Theory

    Simone Biondini🇩🇪 · Lorenzo Tiberi🇮🇹 · Orlando Panella🇮🇹

    We investigate the connection between simplified dark matter models featuring a $t$-channel scalar mediator and the Standard Model Effective Field Theory (SMEFT). We focus on scenarios with fermionic dark matter interacting with leptons, under the assumption of Minimal Flavor Violation. The dimension-six SMEFT Wilson coefficients are computed in the Warsaw basis at one loop, with the aid of Matchete. Assuming a compressed mass spectrum for the dark matter and the mediator, we incorporate coannihilations, Sommerfeld enhancement, and bound-state effects in the relic density calculation. We then analyze the interplay between the dark matter energy density, global SMEFT fits, and direct detection constraints. Our results show that SMEFT bounds, though loop-suppressed, can meaningfully constrain the parameter space for $m_{\chi }\gtrsim 0.5$ TeV and $\mathcal{O}(1)$ portal couplings.

    hep-phJHEP(2025)·6 citations
15. 15*

    Light Neutral Higgs-Boson Production at $e^{+}{e}^{-}$ Colliders in the Complex MSSM and NMSSM: A Full One-Loop Analysis

    S. Heinemeyer🇪🇸 · S. Paßehr🇩🇪 · C. Schappacher🇩🇪

    For future precision analyses of the Higgs boson at $\approx 125$ GeV, $h_{125}$, a precise knowledge of its production and decay properties is mandatory. While in the Standard Model (SM) these calculations are quite advanced, in many models beyond the SM (BSM) a precise calculation is missing so far. We present the calculation of the Higgs-strahlung cross-sections at $e^{+}{e}^{-}$ colliders for the light neutral Higgs boson production in the Next-to-Minimal Supersymmetric SM (NMSSM) with complex parameters (cNMSSM). The evaluation is based on a full one-loop calculation of the production mechanism $e^{+}{e}^{-}\to h_{1}Z$, including soft, hard, and collinear photon radiation. The dependence of the Higgs boson production cross-sections on the relevant cNMSSM parameters is analyzed numerically. In certain scenarios we find sizable corrections to the Higgs-strahlung cross-section. Normally, they reach about $10$ of the tree-level results, but can also exceed 20%. Finally, the calculation is compared to the corresponding one in the Minimal Supersymmetric SM (MSSM). The knowledge of the full one-loop contributions to the Higgs-boson production is particularly important for a sound theoretical intemeasurements at future $e^{+}{e}^{-}$ colliders such as the ILC, CLIC, LCF, FCC-ee, or CEPC. It is planned to implement the evaluation of the Higgs boson production cross-sections into an add-on package to the code FeynHiggs.

    hep-phEPJC(2026)·1 citation
16. 16*

    New Constraints on Neutrino-Dark Matter Interactions: A Comprehensive Analysis

    P. S. Bhupal Dev🇺🇸 · Doojin Kim🇺🇸 · Deepak Sathyan🇺🇸 · Kuver Sinha🇺🇸 · Yongchao Zhang🇨🇳

    We present a comprehensive analysis of the interactions of neutrinos with the dark sector within the simplified model framework. We first derive the exact analytic formulas for the differential scattering cross sections of neutrinos with scalar, fermion, and vector dark matter (DM) for light dark sector models with mediators of different types. We then implement the full catalog of constraints on the parameter space of the neutrino-DM and neutrino-mediator couplings and masses, including cosmological and astrophysical bounds coming from Big Bang Nucleosynthesis, Cosmic Microwave Background, DM and neutrino self-interactions, DM collisional damping, and astrophysical neutrino sources, as well as laboratory constraints from 3-body meson decays and invisible $Z$ decays. We find that most of the benchmarks in the DM mass-coupling plane adopted in previous studies to get an observable neutrino-DM interaction effect are actually ruled out by a combination of the above-mentioned constraints, especially the laboratory ones which are robust against astrophysical uncertainties and independent of the cosmological history. To illustrate the consequences of our new results, we take the galactic supernova neutrinos in the MeV energy range as a concrete example and highlight the difficulties in finding any observable effect of neutrino-DM interactions. Finally, we identify new benchmark points potentially promising for future observational prospects of the attenuation of the galactic supernova neutrino flux and comment on their implications for the detection prospects in future large-volume neutrino experiments such as JUNO, Hyper-K, and DUNE. We also comment on the ultraviolet-embedding of the effective neutrino-DM couplings.

    hep-phastro-ph.COastro-ph.HE22 citations
17. 17*

    PQ-ball and its Real Scalar Analogue in an Expanding Universe

    Kazunori Nakayama🇯🇵 · Masaki Yamada🇯🇵

    We demonstrate the formation of quasi-stable localized scalar configurations in spontaneously symmetry breaking U(1) model by 3+1-dimensional classical lattice simulations. Such configurations are called PQ-balls, as the primary motivation of this kind of configuration is Peccei-Quinn theory under the kinetic misalignment mechanism. Our numerical simulations demonstrate that they can form if the PQ charge is generated through the coherent rotation of a complex scalar field in the complex plane, via dynamics analogous to the Affleck-Dine mechanism. These configurations subsequently decay due to the U(1)-breaking effect induced by spontaneous symmetry breaking. We also demonstrate the formation and decay of oscillons in a similar setup in a real scalar field theory.

    hep-phastro-ph.COJCAP(2025)·0 citations
18. 18*

    Heat Kernel Methods for Multiloop Calculations in Curved Spacetime: Nonzero Spin

    Igor Carneiro🇧🇷 · Gero von Gersdorff🇧🇷

    In a previous paper we have presented a general formalism for computing Feynman diagrams for scalar fields in curved spacetime at any loop order using heat kernel methods. The main technique used is the expansion of the fully off-diagonal heat kernel in Riemann normal coordinates. In this work we extend this to include fields of nonzero spin, in particular spin-$\frac{1}{2}$ fermions.

    ↳ hep-thhep-phJHEP(2025)·1 citation
19. 19*

    Symmetry theta angles and topological Witten effects

    Shi Chen🇺🇸 · Aleksey Cherman🇺🇸 · Maria Neuzil🇺🇸

    We introduce a large class of $\theta$ angles in quantum field theory that we call symmetry $\theta$ angles. Unlike conventional $\theta$ angles whose definition depends on a choice of a path integral, symmetry $\theta$ angles are intrinsic parameters of a quantum field theory that depend only on its symmetries. A frequent consequence of symmetry $\theta$ angles is a phenomenon we call the topological Witten effect, which is a generalization of the standard Witten effect. Topological Witten effects modify which charged operators are attached to topological operators as a function of $\theta$. Physically, topological Witten effects induce generalized Aharonov-Bohm effects. We show that these new $\theta$ angles and Witten effects can appear in many familiar field theories.

    ↳ hep-thhep-ph10 citations
20. 20*

    Coexisting Flux String Vacua from Numerical Kähler Moduli Stabilisation

    Shehu AbdusSalam🇮🇷 · Christopher Hughes🇬🇧 · Fernando Quevedo🇬🇧 · Andreas Schachner🇩🇪

    We present a comprehensive study of Kähler moduli stabilisation in Type IIB flux compactifications, combining advanced numerical techniques with analytical methods. Our JAX-based computational framework enables efficient scanning of the UV parameter space, while incorporating ${\alpha }^{\prime }$ corrections, loop and non-perturbative effects, as well as uplift contributions to the scalar potential. The implementation features rigorous vacuum validation protocols derived from analytic results. We apply our methods to explicit flux compactifications on more than 80,000 Calabi-Yau threefolds with $h^{1,1}\le 6$ Kähler moduli. By systematically scanning over a wide range of values of the flux superpotential $W_0$ and the string coupling $g_s$, we find explicit realisations of every established Kähler moduli stabilisation scenario: for $10^{-15}\le |W_0|\le 10^{-2}$ we obtain both KKLT-like and Kähler uplifted vacua, while for the broader range $10^{-1}\le |W_0|\le 10^2$ we recover LVS as well as LVS-like hybrid solutions. Notably, we discover significant parameter regions where multiple vacua coexist within a single flux potential, including novel configurations pairing AdS, Minkowski, and dS minima with different volume hierarchies. These findings enable, for the first time, the analysis of vacuum decay processes within fixed flux configurations, complementing the established theory of transitions between distinct flux vacua and decays towards decompactification.

    ↳ hep-thhep-phJHEP(2026)·7 citations
21. 21*

    Testing Nambu-Goto approximation of cosmic string by lattice field simulations

    Zizhuo Zhao🇨🇳 · Ligong Bian🇨🇳 · Jing Shu🇨🇳

    The precise calculation of gravitational wave (GW) from cosmic string networks is of significant theoretical and experimental interest. The Nambu--Goto (NG) approximation has long been employed to calculate GW emission from such networks; however, its validity has never been systematically verified. We perform large-scale zero-temperature Abelian-Higgs lattice simulations under different gauge couplings, and compare them with NG predictions. We find excellent agreement in the power-law region for near-global strings but strong deviation for strongly coupled local strings with $m_v/m_s\sim 1$, quantitatively establishing the breakdown of the NG approximation. Additionally, we confirm that particle emission significantly dominates the energy loss of the string network, with the ratio of GW energy to particle energy approximately $10^{-3}$ to $10^{-2}$ for both near-global and local string scenarios.

    ↳ astro-ph.COhep-phhep-thPRD(2026)·3 citations
22. 22*

    Ultralight fuzzy dark matter review

    Andrew Eberhardt🇯🇵 · Elisa G. M. Ferreira🇯🇵

    Ultralight dark matter refers to the lightest potential dark matter candidates. We will focus on the mass range that has been studied using astrophysical and cosmological observations, corresponding to a mass $10^{-24}\mathrm{eV}\lesssim m\lesssim 10^{-18}\mathrm{eV}$. We will discuss the motivations for this mass range. The most studied model in this range corresponds to a minimally coupled, single, classical, spin-0 field comprising all dark matter. However, the work exploring extensions of this model (for example, higher spin, self-coupled, multiple field, and mixed models) will be one of the focuses of this review. The phenomenology associated with ultralight dark matter is rich and includes linear effects on the primordial power spectrum, core structures forming at the center of halos, nonlinear effects resulting in heating of stellar distributions, and non-relativistic effects relating to pulsar signals and black hole superradiance, to name a few. This set of effects has been studied using an equally extensive set of numerical tools. We will summarize the most common ones and discuss their applications and limitations. Ultralight dark matter also has a wide variety of observational constraints, including halo mass functions, the Lyman-alpha forest, halo density profiles, stellar dynamics, and black hole spins. We will review them focusing on the observations made, the method of study, and the major systematics. We will end with a discussion of the current status of the field and future work needed.

    ↳ astro-ph.COastro-ph.GAhep-phhep-th55 citations
23. 23*

    Probing Quarkonium Diffusion in a Magnetized Quark-Gluon Plasma

    Siddhi Swarupa Jena🇮🇳 · Arpan Bhattacharjee🇮🇳 · David Dudal🇧🇪 · Subhash Mahapatra🇮🇳

    Motivated by the potential experimental relevance of magnetically affected heavy-quark diffusion, we consider here a five-dimensional nonlinear Einstein-Born-Infeld-dilaton model to not only holographically model the QCD thermodynamics in a magnetic background, but also to probe the charged inner structure of a heavy quarkonium. The dual model's gravitational equations of motion can be solved in analytical form via the potential reconstruction method. Using a variety of tools -- spectral functions, hydrodynamic expansions or hanging strings -- we study the anisotropic diffusion constants and heavy-quark number susceptibility, each time reporting closed form expressions.

    ↳ hep-thhep-lathep-phPRD(2025)·6 citations
24. 24*

    Hybrid Quark Stars with Quark-Quark Phase Transitions

    Zongcan Yang🇨🇳 · Tianxiong Zeng🇨🇳 · Yan Yan🇨🇳 · Wen-Li Yuan🇨🇳 · Chen Zhang🇨🇳 · Enping Zhou🇨🇳

    We explore the possibility of phase transitions between different quark matter phases occurring within quark stars, giving rise to the hybrid quark stars (HybQSs). First, we obtain the generic phase diagram of possible mass-radius relation forms for the HybQSs. Then, utilizing a well-established general parameterization of interacting quark matter, we construct quark star models featuring sharp first-order quark-quark phase transitions of various types, in contrast to the hadron-quark transition in conventional hybrid stars. We systematically investigate how recent observations, such as the pulsar mass measurement $M_{\mathrm{TOV}}\gtrsim 2M_{\odot }$ and the GW170817's tidal deformability bound ${\Lambda }_{1.4M_{\odot }}<800$, constrain the viable parameter space. We also identified twin stars in some of the HybQS parameter space. Furthermore, we found that the quark-quark phase transitions in hybrid quark stars may also cause the deviation from the approximate universal relation between the dominant postmerger frequency $f_{\mathrm{peak}}$ and tidal deformability ${\Lambda }_{1.35M_{\odot }}$, which was previously believed to only be caused by the hadron-quark phase transitions in hybrid neutron stars. This work unveils new possibilities of phase transitions and the resulting new types of compact stars in realistic astrophysical scenarios.

    ↳ astro-ph.HEgr-qchep-phnucl-thPRD(2026)·11 citations
25. 25*

    Dark photon dark matter constraints at the Taiwan axion search experiment with haloscope

    Yuan-Hann Chang🇹🇼 · Cheng-Wei Chiang🇹🇼 · Hien Thi Doan🇻🇳 · Nick Houston🇨🇳 · Jinmian Li🇨🇳 · Tianjun Li🇨🇳 · Lina Wu🇨🇳 · Xin Zhang🇨🇳

    The dark photon is a well motivated candidate for the dark matter which comprises most of the mass of our visible Universe, leading to worldwide experimental and observational efforts towards its discovery. A primary tool in this search is the cavity haloscope, which facilitates resonantly enhanced conversion to photons from both dark photons and axions. In this context, limits from axion search experiments are often directly converted into dark photon constraints, without re-analyzing the original data. However, this rescaling may not fully capture all of the relevant physics due to various reasons. By re-examining data taken by the Taiwan Axion Search Experiment with Haloscope (TASEH) experiment, we derive a world-leading constraint on the dark photon parameter space, excluding $|ϵ|\gtrsim 2\times 10^{-14}$ in the $19.46-19.84\mu$eV mass range, which exceeds the naïve `rescaling limit' by roughly a factor of two. We emphasize that accounting for the scanning timing information is crucial for deriving limits for the polarized dark photon case. In the data, we also analyze a tentative signal excess with a local significance of 4.7$\sigma$ ($m_X\simeq 19.5\mu$eV) that persists in the absence of a magnetic field. While this excess mimics the behavior of a dark photon signal, it has been excluded by recent results from the HAYSTAC and ORGAN-Q experiments. This case study, nevertheless, highlights the risk of discarding valid dark photon signals when relying on axion-specific magnetic field vetoes.

    ↳ hep-exhep-phPRD(2026)·4 citations
26. 26*

    Gravitational Wave Signatures of Periodic Motion near Higher-Derivative Einstein-Æther Black Holes

    Sayantan Choudhury · Md Khalid Hossain · Gulnur Bauyrzhan · Koblandy Yerzhanov

    Higher-derivative modifications of general relativity are generically expected from effective field theory approaches to quantum gravity, and they arise naturally in Lorentz-violating theories such as Einstein-Ether gravity. In this work, we investigate black hole spacetimes within Einstein-Ether theory supplemented by quadratic curvature corrections, including terms proportional to $R^2$, $R_{\mu \nu }{R}^{\mu \nu }$, and $R_{\mu \nu \lambda \rho }{R}^{\mu \nu \lambda \rho }$. We derive the corrected static, spherically symmetric metric perturbatively and examine its effects on the geodesic structure and gravitational wave emission. In particular, we analyze periodic timelike orbits in this background and compute the associated tensor-mode gravitational waveforms using the quadrupole approximation. Our results demonstrate that even small higher-derivative corrections can induce distinguishable shifts in the orbital dynamics and imprint characteristic phase modulations and harmonic deformations in the gravitational wave signal. These effects modify the frequency spectrum and amplitude envelope of $h_{+}$ and $h_{\times }$ in a manner sensitive to the coupling constants $\alpha$, $\beta$, and $\gamma$, and the Ether parameter $c_{13}$. The resulting signatures provide a potential observational window into ultraviolet deviations from general relativity and Lorentz symmetry in the strong-field regime.

    ↳ gr-qcastro-ph.COhep-phhep-thEPJC(2026)·13 citations
27. 27*

    SPARSE: Scattering Poles and Amplitudes from Radial Schrödinger Equations

    Roberto Bruschini🇺🇸

    We introduce an algorithm for the solution of a system of radial Schrödinger equations describing the inelastic scattering of particles with spin in a partial wave with definite total angular momentum. The system of differential equations is approximated as an ordinary linear nonhomogeneous system using the finite difference method. Dirichlet boundary conditions are imposed at the origin and at an arbitrary large radius. The $K$-matrix for physical energies is calculated from the numerical solutions of the system by comparison to the analytical real solutions at large distances. Scattering poles and amplitudes are calculated from the physical $K$-matrix.

    ↳ quant-phhep-phphysics.comp-ph2 citations
28. 28*

    Quantum Simulation of QED in Coulomb Gauge

    Xiaojun Yao🇺🇸

    A recent work considered quantum simulation of Quantum Electrodynamics on a lattice in the Coulomb gauge with gauge degrees of freedom represented in the occupation basis in momentum space. Here we consider the more efficient representation of the gauge degrees of freedom in field basis in position space and develop a quantum algorithm for real-time simulation. We show that the continuum Coulomb gauge Hamiltonian is equivalent to the temporal gauge Hamiltonian when acting on physical states consisting of fermion and transverse gauge fields. The Coulomb gauge Hamiltonian is discretized by using the Green's function of the discrete Laplacian operator under the Dirichlet boundary conditions. Both the continuum Coulomb gauge Hamiltonian and the discretized one proposed here guarantee that the unphysical longitudinal gauge fields are decoupled and commute with the corresponding Hamiltonian. Thus there is no need to impose any constraint. The local gauge field basis and the canonically conjugate variable basis are swapped efficiently using the quantum Fourier transform. We prove that the qubit cost to represent physical states and the gate count for real-time simulation scale polynomially with the lattice size, energy, time, accuracy, and Hamiltonian parameters in lattice units. The gate cost here for implementing the time evolution of the gauge field is reduced at least by a factor on the order of $10^8$ for modest lattice size and accuracy level compared with the previous work.

    ↳ quant-phhep-lathep-phnucl-thPRD(2026)·10 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.