Fri·Nov 8, 2024Friday·November 8, 2024

1. 01*

   Investigating the Seebeck effect of the QGP medium using a novel relaxation time approximation model

   Anowar Shaikh🇮🇳 · Shubhalaxmi Rath🇨🇱 · Sadhana Dash🇮🇳 · Binata Panda🇮🇳

   The highly energetic particle medium formed in the ultrarelativistic heavy ion collision displays a notable difference in the temperatures between its central and peripheral regions. This temperature gradient can generate an electric field within the medium, a phenomenon referred to as the Seebeck effect. We have estimated the Seebeck coefficient for a dense quark-gluon plasma medium by using the relativistic Boltzmann transport equation in the recently developed novel relaxation time approximation (RTA) model within the kinetic theory framework. This study explores the Seebeck coefficient of individual quark flavors as well as the entire partonic medium. Our observation indicates that, for given current quark masses, the magnitude of the Seebeck coefficient for each quark flavor as well as for the partonic medium decreases as the temperature rises and increases as the chemical potential increases. Furthermore, we have investigated the Seebeck effect by considering the partonic interactions within the quasiparticle model. In addition, we have presented a comparison between our findings and the results of the standard RTA model. We have observed that the Seebeck coefficient of the QGP medium gets conspicuously decreased in the novel RTA model as compared to that in the standard RTA model. A decreased Seebeck coefficient in the novel RTA model describes a smaller magnitude of induced electric field in the medium than that estimated by the standard RTA model. However, the rate of decline gets gradually smaller as the medium gets hotter for both the current quark mass scenario and the quasiparticle mass scenario. It is also found that, in the noninteracting case, the Seebeck coefficient possesses a slightly negative value in the high temperature region, unlike the quasiparticle description, where the Seebeck coefficient remains positive for the entire temperature range.

   hep-phhep-thnucl-thPRD(2025)·5 citations
2. 02*

   Probing a $Z^{\prime }$ gauge boson via neutrino trident scattering in the Forward Physics Facility at the LHC and FCC

   Reinaldo Francener🇧🇷 · Victor P. Goncalves🇧🇷 · Diego R. Gratieri🇧🇷

   The study of neutrino physics at the Large Hadron Collider is already a reality, and a broad neutrino physics program is expected to be developed in forthcoming years at the Forward Physics Facility (FPF). In particular, the neutrino trident scattering process, which is a rare Standard Model process, is expected to be observed for the first time with a statistical significance of $5\sigma$ using the FASER$\nu$2 detector. Moreover, similar studies are expected to be performed in the proposed Future Circular Collider (FCC). Such perspectives motivate the investigation of the impact of New Physics on the predictions for the corresponding number of events. In this letter, we consider the $L_{\mu }-L_{\tau }$ model, which predicts an additional massive neutral gauge boson, $Z^{\prime }$, that couples to neutrino and charged leptons of the second and third families, and estimate the production of a dimuon system in the neutrino trident scattering at the FASER$\nu$2 assuming different models for the incoming neutrino flux at the LHC and FCC energies. We derive the associated sensitivity and demonstrate that the FPF@LHC is not able to improve the current bounds on the $L_{\mu }-L_{\tau }$ model, while a future measurement of the dimuons produced in neutrino trident events in the FPF@FCC will extend the coverage of the parameter space in comparison to previous experiments.

   hep-phhep-exEPJC(2025)·3 citations
3. 03*

   Split Cherenkov radiation in isotropic chiral matter

   Eduardo Barredo-Alamilla🇷🇺 · Luis F. Urrutia🇲🇽 · Maxim A. Gorlach🇷🇺

   Chiral matter exhibits unique electromagnetic responses due to the macroscopic manifestation of the chiral anomaly as anomalous transport currents. Here, we study the modification of electromagnetic radiation in isotropic chiral matter characterized by an axion coupling that varies linearly over time $\theta (t)=b_{0}t$. Using Carroll-Field-Jackiw electrodynamics, we derive the causal Green's function to investigate the stability and radiation properties of the system. Even though the plane-wave modes of isotropic chiral matter exhibit imaginary frequencies for long wavelengths, which might suggest instability in the system, we show that their contribution is confined to the near-field region. Also we find no exponentially growing fields at arbitrarily large times, so that stability is preserved. Under these conditions the radiation yields a positive energy flux, although this is not an inherent property of the general definition. In the case of a fast-moving charge, we confirm the existence of vacuum Cherenkov radiation and show that, for refractive indices $n>1$, the Cherenkov cone can split into two concentric cones with opposite circular polarizations. This split, governed by the speed of the particle $v$, $n$ and $b_0$, resembles the optical spin-Hall effect and offers potential applications for creating circularly polarized terahertz (THz) light sources. Our Green's function approach provides a general method for analyzing radiation in chiral matter, from Weyl semimetals to quark-gluon plasmas, and can be extended to systems such as oscillating dipoles and accelerated charges.

   hep-phcond-mat.mes-hallhep-th0 citations
4. 04*

   Ultra High Energy Cosmic Rays in light of the Lorentz Invariance Violation Effects within the Proton Sector

   Guo-Li Liu🇨🇳 · Xinbo Su🇨🇳 · Fei Wang🇨🇳

   Tiny Lorentz Invariance Violation (LIV) effects, potentially arising from quantum gravity-induced spacetime structures, may also manifest in the proton sector, offering a plausible pathway to test Planck-scale physics through high-energy cosmic phenomena. Our analysis reveals that even minuscule LIV effects in the proton sector can significantly elevate the photon threshold energy for photopion production to $\mathcal{O}$(0.1 to $10^3$ eV), orders of magnitude higher than in Lorentz-symmetric scenarios. Consequently, protons in ultra-high-energy cosmic rays (UHECRs) can propagate for very long distances without significant energy loss via photopion interactions with cosmic microwave background (CMB) photons. This suppression of attenuation may provide a plausible explanation for the observed cosmic-ray events exceeding the Greisen-Zatsepin-Kuzmin (GZK) cutoff energy. We further demonstrate that when both leading-order and next-to-leading-order LIV effects are considered, higher-order LIV contributions induce discontinuous transitions in the GZK cutoff energy spectrum. Observations of proton-dominated UHECRs beyond the GZK threshold could provide constraints the LIV energy scale. Offering insights into the ultraviolet regime of LIV theories near the Planck scale, UHECRs may serve as a sensitive probe of LIV and provide a means to test quantum gravity predictions by constraining deviations from Lorentz symmetry in extreme-energy regimes.

   hep-phastro-ph.HEEPJC(2025)·1 citation
5. 05*

   Extending the Dark Matter Reach of Water Cherenkov Detectors using Jupiter

   Sandra Robles🇬🇧 · Stephan A. Meighen-Berger🇦🇺

   We propose the first method for water Cherenkov detectors to constrain GeV-scale dark matter (DM) below the solar evaporation mass. While previous efforts have highlighted the Sun and Earth as DM capture targets, we demonstrate that Jupiter is a viable target. Jupiter's unique characteristics, such as its lower core temperature and significant gravitational potential, allow it to capture and retain light DM more effectively than the Sun, particularly in the mass range below 4 GeV where direct detection sensitivity diminishes. Our calculations provide the first sensitivity estimates to GeV-scale annihilating DM within Jupiter, predicting Hyper-K can reach spin dependent cross sections as low as ${\sigma }_{p\chi }^{\mathrm{SD}}=2\times 10^{-35}{\mathrm{cm}}^2$ for DM masses below 2 GeV. This surpasses current solar limits and direct detection results. We additionally provide estimates for Super-K ORCA, and the IceCube-Upgrade, showing that these experiments could provide complimentary bounds to direct detection experiments.

   hep-phastro-ph.COastro-ph.EPastro-ph.IM+1PRD(2025)·10 citations
6. 06*

   Improving smuon searches with Neural Networks

   Alan S. Cornell🇿🇦 · Benjamin Fuks🇫🇷 · Mark D. Goodsell🇫🇷 · Anele M. Ncube🇿🇦

   We demonstrate that neural networks can be used to improve search strategies, over existing strategies, in LHC searches for light electroweak-charged scalars that decay to a muon and a heavy invisible fermion. We propose a new search involving a neural network discriminator as a final cut and show that different signal regions can be defined using networks trained on different subsets of signal samples (distinguishing low-mass and high-mass regions). We also present a workflow using publicly-available analysis tools, that can lead, from background and signal simulation, to network training, through to finding projections for limits using an analysis and $\mathtt{ONNX}$ libraries to interface network and recasting tools. We provide an estimate of the sensitivity of our search from Run 2 LHC data, and projections for higher luminosities, showing a clear advantage over previous methods.

   hep-phhep-exEPJC(2025)·7 citations
7. 07*

   Probing CP-violating Higgs-gauge Boson Couplings at Future Muon Collider

   Emre Gurkanli🇹🇷 · Serdar Spor🇹🇷

   We explore the sensitivity of future muon colliders to CP-violating interactions in the Higgs sector, specifically focusing on the process ${\mu }^{-}{\mu }^{+}\to h\overline{{\nu }_l}{\nu }_l\to b\bar{b}\overline{{\nu }_l}{\nu }_l$. Using a model-independent approach within the framework of the Standard Model Effective Field Theory (SMEFT), we analyze the contribution of dimension-six operators to Higgs-gauge boson couplings, emphasizing CP-violating effects. To simulate the process, all signal and background events are generated through MadGraph. The analysis provides 95\% confidence level limits on the relevant Wilson coefficients ${\tilde{c}}_{HB}$, ${\tilde{c}}_{HW}$, ${\tilde{c}}_{\gamma }$, with a comparative discussion of existing experimental and phenomenological constraints. Our best constraints on the ${\tilde{c}}_{HB}$, ${\tilde{c}}_{HW}$, ${\tilde{c}}_{\gamma }$ with an integrated luminosity of 10 ab${}^{-1}$ are $[-0.017428;0.018991]$, $[-0.002880;0.002586]$ and $[-0.010784;0.011381]$, respectively. In this context, this study highlights the capability of future muon collider experiments to probe new physics in the Higgs sector, potentially offering tighter constraints on CP-violating Higgs-gauge boson interactions than those provided by current colliders.

   hep-phPTEP(2025)·7 citations
8. 08*

   Exploring Charged Higgs at the Future Circular Collider (FCC): A Review of Two-Higgs-Doublet Models

   Ijaz Ahmed🇵🇰 · Basit Ali🇨🇿 · M.S. Amjad🇵🇰 · M. Jamil🇰🇷 · Saba Shafaq🇵🇰 · Usman Ahmad🇵🇰

   This paper reports on the theoretical investigation of charged Higgs bosons and their coupling to fermions within the Two Higgs Doublet Model (THDM). The study focuses on the discovery potential of charged Higgs bosons predicted in Types III and IV at the future Circular Hadron-Hadron Collider (FCC-hh) with a center-of-mass energy of (\sqrt{s} = 100) TeV. By analyzing their decays, couplings to fermions, branching ratios, and production cross-section via (pp \rightarrow tH^-), we investigate the signatures of charged Higgs bosons, including kinematical distributions based on the background processes of (b\bar{b}) quarks.

   hep-phInt.J.Mod.Phys.A(2026)·0 citations
9. 09*

   Berry phase in axion physics, SM global structure, and generalized symmetries

   Qing-Hong Cao🇨🇳 · Shuailiang Ge🇨🇳 · Yandong Liu🇨🇳 · Jun-Chen Wang🇨🇳

   We investigate the Berry phase arising from axion-photon and axion-fermion interactions. The effective Hamiltonians in both systems share the same form, enabling a unified description of the Berry phase and providing a novel perspective on axion experiments. We conceptually propose a new photon-ring experiment for axion detection. Furthermore, we demonstrate that measuring the axion-induced Berry phase offers a unique method for probing the global structure of the Standard Model gauge group and axion-related generalized symmetries.

   hep-phastro-ph.COhep-exhep-thPLB(2026)·6 citations
10. 10*

    Search for Neutral Triple Gauge Couplings with $ZZ$ Production at Future Electron Positron Colliders

    Yu-Chen Guo🇨🇳 · Chun-Jing Pan🇨🇳 · Man-Qi Ruan🇨🇳 · Ji-Chong Yang🇨🇳

    This study investigates Neutral Triple Gauge Couplings (nTGCs) through $ZZ$ production at future electron-positron colliders. The impact of beam polarization on cross section is analyzed. We compare the signals and backgrounds for five different $ZZ$ decay channels and present our event selection strategies for future $e^{+}{e}^{-}$ colliders. The expected coefficient constraints for each decay channels are provided, and final expected constraints are derived by combining results from the different decay patterns. Our analysis indicates that future electron-positron colliders will have significantly enhanced detection capabilities for nTGCs compared to the current LHC experiments, with expected improvements in constraints by one to two orders of magnitude.

    hep-phPRD(2025)·5 citations
11. 11*

    Aspects of Non-local QED and the Weak Gravity Conjecture

    Fayez Abu-Ajamieh🇮🇳 · Nobuchika Okada🇺🇸 · Sudhir K. Vempati🇮🇳

    We use the Weak Gravity Conjecture (WGC) to investigate the impact of charge dequantization arising from non-local QED on the scale of non-locality of neutrinos. We find this scale to be <= 87 TeV, which could be probed in future colliders. We also investigate the electric force and potential in non-local QED and use them to reformulate the Weak Gravity Conjecture (WGC) in non-local QED.

    hep-phEPJC(2025)·3 citations
12. 12*

    Modular domain walls and gravitational waves

    Stephen F. King🇬🇧 · Xin Wang🇬🇧 · Ye-Ling Zhou🇨🇳

    We discuss modular domain walls and gravitational waves in a class of supersymmetric models where quark and lepton flavour symmetry emerges from modular symmetry. In such models a single modulus field $\tau$ is often assumed to be stabilised at or near certain fixed point values such as $\tau =\mathrm{i}$ and $\tau =\omega$ (the cube root of unity), in its fundamental domain. We show that, in the global supersymmetry limit of certain classes of potentials, the vacua at these fixed points may be degenerate, leading to the formation of modular domain walls in the early Universe. Taking supergravity effects into account, in the background of a fixed dilaton field $S$, the degeneracy may be lifted, leading to a bias term in the potential allowing the domain walls to collapse. We study the resulting gravitational wave spectra arising from the dynamics of such modular domain walls, and assess their observability by current and future experiments, as a window into modular flavour symmetry.

    hep-phastro-ph.COhep-thJCAP(2025)·5 citations
13. 13*

    Dispersion theory of nucleon (nucleus) Compton scattering spin polarizabilities and quasi-optical $\gamma$-ray polarization plane rotation and birefringence effect in a matter with polarized protons (nuclei)

    Vladimir Baryshevsky🇧🇾

    Experimental observation of quasi-optical phenomenon of $\gamma$-quanta polarization plane rotation in matter with polarized proton (nuclei) is demonstrated to be possible. This effect is similar to the magneto-optic Faraday effect (Faraday optical rotation). Quasi-optical birefringence effect for $\gamma$-quanta in matter with polarized nuclei having spin $S\ge 1$ could also be observed. The latter effect is similar to double refraction (birefringence) of light in uniaxial and biaxial crystals. The above phenomena open up possibility to investigate how spin vector and tensor polarizabilities depend on $\gamma$-quanta energy. In particular, studying the effect of $\gamma$-quanta polarization plane rotation, it is possible to find the range of $\gamma$-quanta energies, which is associated with strong dependence of spin polarizability on $\gamma$-quanta energy.

    hep-ph1 citation
14. 14*

    How fast does the WallGo? A package for computing wall velocities in first-order phase transitions

    Andreas Ekstedt🇸🇪 · Oliver Gould🇬🇧 · Joonas Hirvonen🇬🇧 · Benoit Laurent🇨🇦 · Lauri Niemi🇫🇮 · Philipp Schicho🇨🇭 · Jorinde van de Vis🇨🇭

    WallGo is an open source software for the computation of the bubble wall velocity in first-order cosmological phase transitions. It also computes the energy budget available for the generation of gravitational waves. The main part of WallGo, built in Python, determines the wall velocity by solving the scalar-field(s) equation of motion, the Boltzmann equations and energy-momentum conservation for the fluid velocity and temperature. WallGo also includes two auxiliary modules: WallGoMatrix, which computes matrix elements for out-of-equilibrium particles, and WallGoCollision, which performs higher-dimensional integrals for Boltzmann collision terms. Users can implement custom models by defining an effective potential and specifying a list of out-of-equilibrium particles and their interactions. As the first public software to compute the wall velocity including out-of-equilibrium contributions, WallGo improves the precision of the computation compared to common assumptions in earlier computations. It utilises a spectral method for the deviation from equilibrium and collision terms that provides exponential convergence in basis polynomials, and supports multiple out-of-equilibrium particles, allowing for Boltzmann mixing terms. WallGo is tailored for non-runaway wall scenarios where leading-order coupling effects dominate friction. While this work introduces the software and the underlying theory, a more detailed documentation can be found in https://wallgo.readthedocs.io.

    hep-phastro-ph.COJHEP(2025)·78 citations
15. 15*

    Neutrino Self-interaction and Weak Mixing Angle Measurements

    Yue Zhang🇨🇦

    Neutrino self-interaction with a larger ``Fermi constant'' is often resorted to for understanding various puzzles of our universe. We point out that a light, neutrinophilic scalar particle $\varphi$ through radiative correction leads to an energy-scale dependence in the neutrino-$Z$-boson gauge coupling. The driver behind this phenomenon is a large separation between the mass scales of $\varphi$ and additional heavy particles needed for gauge invariance. This is a generic effect insensitive to details of the UV completion. We show that the running can change the $Z\nu \bar{\nu }$ coupling by several percent and affect the measurement of weak mixing angle through neutrino neutral-current processes. We discuss the interplay between the running of the $Z\nu \bar{\nu }$ coupling and ${\sin }^2{\theta }_W$ in various experimental observables. It is possible to disentangle the two effects with more than one precise measurement.

    hep-phastro-ph.COhep-exPRD(2025)·10 citations
16. 16*

    Bubble-wall speed with loop corrections

    Andrii Dashko🇩🇪 · Andreas Ekstedt🇸🇪

    In this paper, we investigate the dynamics of the nucleating scalar field during the first-order phase transitions by incorporating one-loop corrections of classical fluctuations. We assume that a high-temperature expansion is valid\te where the mass of the scalar field is significantly smaller than the temperature\te so that we can treat the bubble-wall dynamics in a regime where quantum fluctuations can be integrated out. We present a systematic framework for calculating classical loop corrections to the wall speed; contrast our results with traditional methods based on the derivative expansion; show that the latent heat can differ from the effective-potential result; and discuss general hydrodynamic corrections. Finally, we show an application of the presented framework for a simple scalar field model, finding that the one-loop improvement decreases the wall speed and that an effective-potential approximation underestimates full one-loop corrections by about a factor of two.

    hep-phhep-thJHEP(2025)·12 citations
17. 17*

    Quantum Magic and Computational Complexity in the Neutrino Sector

    Ivan Chernyshev🇺🇸 · Caroline E. P. Robin🇩🇪 · Martin J. Savage🇺🇸

    We consider the quantum magic in systems of dense neutrinos undergoing coherent flavor transformations, relevant for supernova and neutron-star binary mergers. Mapping the three-flavor-neutrino system to qutrits, the evolution of quantum magic is explored in the single scattering angle limit for a selection of initial tensor-product pure states for $N_{\nu }\le 8$ neutrinos. For $|{\nu }_e{⟩}^{\otimes N_{\nu }}$ initial states, the magic, as measured by the $\alpha =2$ stabilizer Renyi entropy $M_2$, is found to decrease with radial distance from the neutrino sphere, reaching a value that lies below the maximum for tensor-product qutrit states. Further, the asymptotic magic per neutrino, $M_2/N_{\nu }$, decreases with increasing $N_{\nu }$. In contrast, the magic evolving from states containing all three flavors reaches values only possible with entanglement, with the asymptotic $M_2/N_{\nu }$ increasing with $N_{\nu }$. These results highlight the connection between the complexity in simulating quantum physical systems and the parameters of the Standard Model.

    ↳ quant-phhep-phnucl-thPRResearch(2025)·60 citations
18. 18*

    Vacuum Amplification of Chiral Gravitational Waves and the Stochastic Gravitational Wave Background

    Stephon Alexander🇺🇸 · Heliudson Bernardo🇺🇸 · Yiya Selina Li🇺🇸 · Cooper Niu🇺🇸

    We investigate cosmological vacuum amplification of gravitational waves in dynamical Chern-Simons gravity. We develop a comprehensive framework to compute graviton production induced by the parity violating Pontryagin coupling and study its imprint on the stochastic gravitational wave background energy power spectrum. We explore gravitational vacuum amplification in four concrete scenarios for the evolution of the Chern-Simons pseudoscalar. We show that a parity-violating contribution dominates over an initially flat spectrum when the velocity of the pseudoscalar quickly interpolates between two asymptotically constant values or when it is nonvanishing and constant through a finite period of time. This is also the case when we parametrize the pseudoscalar evolution by a perfect fluid with radiation- and dust-like equations of state for large enough values of its energy density. The resulting spectra are compared with the sensitivity curves of current and future gravitational wave observational searches.

    ↳ gr-qcastro-ph.COastro-ph.HEhep-ph+1PRD(2025)·10 citations
19. 19*

    FLAG Review 2024

    Y. Aoki🇯🇵 · T. Blum🇺🇸 · S. Collins🇩🇪 · L. Del Debbio🇬🇧 · M. Della Morte🇩🇰 · P. Dimopoulos🇮🇹 · X. Feng🇨🇳 · M. Golterman🇺🇸 · Steven Gottlieb🇺🇸 · R. Gupta🇺🇸 · G. Herdoíza🇪🇸 · P. Hernandez🇪🇸 and 19 other authors

    We review lattice results related to pion, kaon, $D$-meson, $B$-meson, and nucleon physics with the aim of making them easily accessible to the nuclear and particle physics communities. More specifically, we report on the determination of the light-quark masses, the form factor $f_{+}(0)$ arising in the semileptonic $K\to \pi$ transition at zero momentum transfer, as well as the decay-constant ratio $f_K/f_{\pi }$ and its consequences for the CKM matrix elements $V_{us}$ and $V_{ud}$. We review the determination of the $B_K$ parameter of neutral kaon mixing as well as the additional four $B$ parameters that arise in theories of physics beyond the Standard Model. For the heavy-quark sector, we provide results for $m_c$ and $m_b$ as well as those for the decay constants, form factors, and mixing parameters of charmed and bottom mesons and baryons. These are the heavy-quark quantities most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. We review the status of lattice determinations of the strong coupling constant ${\alpha }_s$. We review the determinations of nucleon charges from the matrix elements of both isovector and flavour-diagonal axial, scalar and tensor local quark bilinears, and momentum fraction, helicity moment and the transversity moment from one-link quark bilinears. We also review determinations of scale-setting quantities. Finally, in this review we have added a new section on the general definition of the low-energy limit of the Standard Model.

    ↳ hep-lathep-phPRD(2026)·435 citations
20. 20*

    Conversations and Deliberations: Non-Standard Cosmological Epochs and Expansion Histories

    Brian Batell🇺🇸 · Keith R. Dienes🇺🇸 · Brooks Thomas🇺🇸 · Scott Watson🇺🇸 · Rouzbeh Allahverdi🇺🇸 · Mustafa Amin🇺🇸 · Kimberly K. Boddy🇺🇸 · M. Sten Delos🇺🇸 · Adrienne L. Erickcek🇺🇸 · Akshay Ghalsasi🇺🇸 · John T. Giblin Jr.🇺🇸 · James Halverson🇺🇸 and 8 other authors

    This document summarizes the discussions which took place during the PITT-PACC Workshop entitled "Non-Standard Cosmological Epochs and Expansion Histories," held in Pittsburgh, Pennsylvania, Sept. 5-7, 2024. Much like the non-standard cosmological epochs that were the subject of these discussions, the format of this workshop was also non-standard. Rather than consisting of a series of talks from participants, with each person presenting their own work, this workshop was instead organized around free-form discussion blocks, with each centered on a different overall theme and guided by a different set of Discussion Leaders. This document is not intended to serve as a comprehensive review of these topics, but rather as an informal record of the discussions that took place during the workshop, in the hope that the content and free-flowing spirit of these discussions may inspire new ideas and research directions.

    ↳ astro-ph.COhep-phhep-thInt.J.Mod.Phys.A(2025)·36 citations
21. 21*

    Nailing down the theoretical uncertainties of $\overline{\mathrm{D}}$ spectrum produced from dark matter

    Mattia Di Mauro🇮🇹 · Nicolao Fornengo🇮🇹 · Adil Jueid🇰🇷 · Roberto Ruiz de Austri🇪🇸 · Francesca Bellini🇮🇹

    The detection of cosmic antideuterons ($\overline{\mathrm{D}}$) at kinetic energies below a few GeV/n could provide a smoking gun signature for dark matter (DM). However, the theoretical uncertainties of coalescence models have represented so far one of the main limiting factors for precise predictions of the $\overline{\mathrm{D}}$ flux. In this Letter we present a novel calculation of the $\overline{\mathrm{D}}$ source spectra, based on the Wigner formalism, for which we implement the Argonne $v_{18}$ antideuteron wavefunction that does not have any free parameters related to the coalescence process. We show that the Argonne Wigner model excellently reproduces the $\overline{\mathrm{D}}$ multiplicity measured by ALEPH at the $Z$-boson pole, which is usually adopted to tune the coalescence models based on different approaches. Our analysis is based on Pythia~8 Monte Carlo event generator and the state-of-the-art Vincia shower algorithm. We succeed, with our model, to reduce the current theoretical uncertainty on the prediction of the $\overline{\mathrm{D}}$ source spectra to a few percent, for $\overline{\mathrm{D}}$ kinetic energies relevant to DM searches with GAPS and AMS, and for DM masses above a few tens of GeV. This result implies that the theoretical uncertainties due to the coalescence process are no longer the main limiting factor in the predictions. We provide the tabulated source spectra for all the relevant DM annihilation/decay channels and DM masses between 5 GeV and 100 TeV, on the CosmiXs github repository (https://github.com/ajueid/CosmiXs.git).

    ↳ astro-ph.HEhep-phPRL(2025)·19 citations
22. 22*

    Lattice simulations of axion-U(1) inflation: gravitational waves, magnetic fields, and scalar statistics

    Ramkishor Sharma🇨🇿 · Axel Brandenburg🇸🇪 · Kandaswamy Subramanian🇬🇧 · Alexander Vikman🇨🇿

    We numerically study axion-U(1) inflation, focusing on the regime where the coupling between axions and gauge fields results in significant backreaction from the amplified gauge fields during inflation. These amplified gauge fields not only generate high-frequency gravitational waves (GWs), but also enhance spatial inhomogeneities in the axion field. GWs serve as key probe for constraining the coupling strength between the axion and gauge fields. We find that, when backreaction is important during inflation, the constraints on the coupling strength due to GW overproduction are relaxed compared to previous studies, in which backreaction matters only after inflation. Moreover, our results suggest that the probability density function (PDF) of axion fluctuations tends toward a Gaussian distribution even in cases where gauge field backreaction is important only after inflation. This aligns with previous studies where the same effect was observed for cases with strong backreaction during inflation. This finding can be crucial for future studies of primordial black hole (PBH) formation, which can further constrain the coupling strength. We also calculate the spectrum of the produced magnetic fields in this model and find that their strength is compatible with the observed lower limits.

    ↳ astro-ph.COhep-phhep-thJCAP(2025)·39 citations
23. 23*

    Modification of the Jet Energy-Energy Correlator in Cold Nuclear Matter

    Yu Fu🇺🇸 · Berndt Müller🇺🇸 · Chathuranga Sirimanna🇺🇸

    We compute medium corrections to the energy-energy correlator (EEC) for jets in electron-nucleus collisions at leading order in the QCD coupling and the interaction of the jet with the medium. We derive an analytical expression for the modification of the EEC as a function of the opening angle and show that the modification is strongest at large angles within the jet cone. We obtain explicit results for the dependence of the modification on the jet energy, the scattering power of cold nuclear matter, and the path length within the medium. We extend our calculations to gluon jets in proton-nucleus collisions and compare our results with recent preliminary data for proton-lead collisions at the LHC. We also discuss the role of comovers on the EEC in p+Pb collisions.

    ↳ nucl-thhep-phPRL(2025)·32 citations
24. 24*

    Causality in dissipative relativistic magnetohydrodynamics

    Raphael E. Hoult🇨🇦 · Pavel Kovtun🇨🇦

    We explore the relationship between linear and non-linear causality in theories of dissipative relativistic fluid dynamics. While for some fluid-dynamical theories, a linearized causality analysis can be used to determine whether the full non-linear theory is causal, for others it can not. As an illustration, we study relativistic viscous magnetohydrodynamics supplemented by a neutral-particle current, with resistive corrections to the conservation of magnetic flux. The dissipative theory has 10 transport coefficients, including anisotropic viscosities, electric resistivities, and neutral-particle conductivities. We show how causality properties of this magnetohydrodynamic theory, in the most general fluid frame, may be understood from the linearized analysis.

    ↳ hep-thgr-qchep-phJHEP(2025)·9 citations
25. 25*

    Systematic study of flow of protons and light clusters in intermediate-energy heavy-ion collisions with momentum-dependent potentials

    Viktar Kireyeu🇷🇺 · Vadim Voronyuk🇷🇺 · Michael Winn🇫🇷 · Susanne Gläßel🇩🇪 · Jörg Aichelin🇫🇷 · Christoph Blume🇩🇪 · Elena Bratkovskaya🇩🇪 · Gabriele Coci🇮🇹 · Jiaxing Zhao🇩🇪

    We study the influence of the nuclear equation-of-state (EoS) on collective observables -- the directed ($v_1$) and elliptic flow ($v_2$) of nucleons and light clusters -- in heavy-ion collisions at GeV energies using the Parton-Hadron-Quantum-Molecular Dynamics (PHQMD) approach. A novel development in this work is the inclusion of a momentum-dependent nucleon potential in the PHQMD in addition to the static, density-dependent Skyrme interaction. This enables three distinct EoS scenarios: two static ("soft" and "hard", differing in compressibility) and a soft, momentum-dependent EoS calibrated to $pA$ elastic scattering data. We find a strong EoS sensitivity in proton and cluster rapidity and $p_T$ distributions: soft and soft momentum-dependent EoS yield similar results, markedly different from the hard EoS. Softening the EoS reduces proton yields at midrapidity while enhancing light-cluster production. The EoS also affects flow observables differently for nucleons and clusters. For protons, a soft momentum-dependent potential increases slightly the magnitude of $v_1$ and $v_2$ relative to the hard EoS, whereas cluster flows are nearly similar. The soft momentum-dependent EoS provides an overall good agreement with experimental data from HADES and FOPI Collaborations while the soft EOS is not in line with the data. A scaling of $v_2$ with cluster mass number $A$ is observed at midrapidity for low $p_T$, which breaks at higher $p_T$. Finally, we examine the sensitivity of flow observables to deuteron production mechanisms. Deuterons formed via MST clustering exhibit different flow patterns from those produced by coalescence at freeze-out, indicating that flow harmonics may help discriminate between cluster formation scenarios.

    ↳ nucl-thhep-exhep-phnucl-exPRC(2026)·19 citations
26. 26*

    A Primer on Dark Matter

    Csaba Balazs🇦🇺 · Torsten Bringmann🇳🇴 · Felix Kahlhoefer🇩🇪 · Martin White🇦🇺

    Dark matter is a fundamental constituent of the universe, which is needed to explain a wide variety of astrophysical and cosmological observations. Although the existence of dark matter was first postulated nearly a century ago and its abundance is precisely measured, approximately five times larger than that of ordinary matter, its underlying identity remains a mystery. A leading hypothesis is that it is composed of new elementary particles, which are predicted to exist in many extensions of the Standard Model of particle physics. In this article we review the basic evidence for dark matter and the role it plays in cosmology and astrophysics, and discuss experimental searches and potential candidates. Rather than targeting researchers in the field, we aim to provide an accessible and concise summary of the most important ideas and results, which can serve as a first entry point for advanced undergraduate students of physics or astronomy.

    ↳ astro-ph.COhep-phAstrophysics(2026)·42 citations
27. 27*

    Gravitational Waves from Primordial Black Hole Dark Matter Spikes

    Wei-Xiang Feng🇨🇳 · Simeon Bird🇺🇸 · Hai-Bo Yu🇺🇸

    The origin of the binary black hole mergers observed by LIGO--Virgo--KAGRA remains an open question. We calculate the merger rate from primordial black holes (PBHs) within the density spike around supermassive black holes (SMBHs) at the centers of galaxies. We show that the merger rate within the spike is comparable to that within the wider dark matter halo. We also calculate the extreme mass ratio inspiral (EMRI) signal from PBHs hosted within the density spike spiralling into their host SMBHs due to gravitational wave emission. We predict that LISA may detect $\sim 10^4$ of these EMRIs with a signal-to-noise ratio threshold of 20 within a 4 yr observation run, if all dark matter is made up of $\sim 30{\mathrm{M}}_{\odot }$ PBHs. Uncertainties in our rates come from the uncertain mass fraction of PBHs within the dark matter spike, relative to the host central SMBHs, which defines the parameter space LISA can constrain.

    ↳ astro-ph.COastro-ph.HEgr-qchep-phApJ(2025)·8 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.