Mon·Aug 4, 2025Monday·August 4, 2025

1. 01*

   Worldline Modeling of Ultra-Intense Lasers for N-photon Scattering Processes

   Ivan Ahumada🇬🇧 · Patrick Copinger🇬🇧 · James P. Edwards🇬🇧 · Karthik Rajeev🇬🇧

   The modeling of present and future ultra-intense lasers demands techniques that go beyond the standard diagrammatic approach to non-perturbatively fully capture the effects of strong fields. We illustrate the first-quantized path integral representation for strong-field quantum electrodynamics as a means of accessing the laser being treated as a background field, which is treated without recourse to perturbation theory. We examine an all-multiplicity construction for $N-$photon scattering processes for complex scalars and spinors, showing compact Master Formulae for tree-level scattering. Several background fields are considering including: plane waves, impulsive PP-waves, non-null fields, and homogeneous fields (constant-crossed fields) with low-energy external photons.

   hep-phhep-thPhys.Plasmas(2025)·1 citation
2. 02*

   Distinguishing between Dirac and Majorana neutrinos at FASER

   ShivaSankar K.A. · Alakabha Datta🇺🇸 · Danny Marfatia🇺🇸

   Some of the simplest models for the origin of neutrino mass involve right-handed neutrinos (RHNs), which could be either Dirac or Majorana particles - a distinction that has profound implications for lepton number conservation and the fundamental nature of neutrinos. We investigate the potential of the FASER experiment to distinguish between these two possibilities using signatures predicted by the Standard Model Neutrino Effective Field Theory (SMNEFT), where RHNs interact with Standard Model particles through higher-dimensional operators. We focus on RHNs produced via $B$, $D$, $K$, and $\pi$ meson decays at the Large Hadron Collider and their subsequent three-body decays within the FASER detector. The kinematic and angular distributions of the decay products in the RHN rest frame differ significantly for Dirac and Majorana RHNs, and these differences manifest as distinct spatial distributions of electron-positron pairs at FASER. Using Monte Carlo simulations and a ${\chi }^2$ analysis, we demonstrate that these spatial observables provide a robust experimental probe for determining the Dirac or Majorana nature of RHNs. For select production and decay operator combinations and RHN masses around 0.1 GeV, FASER can achieve discrimination at the $3\sigma$ level.

   hep-phhep-exJHEP(2026)·2 citations
3. 03*

   Variational Neural Network Approach to QFT in the Field Basis

   Kevin Braga🇺🇸 · Nobuo Sato🇺🇸 · Adam P. Szczepaniak🇺🇸

   We present a variational neural network approach for solving quantum field theories in the field basis, focusing on the free Klein-Gordon model formulated in momentum space. While recent studies have explored neural-network-based variational methods for scalar field theory in position space, a systematic benchmark of the analytically solvable Klein-Gordon ground state -- particularly in the momentum-space field basis -- has been lacking. In this work, we represent the ground-state wavefunctional as a neural network defined on a discretized set of field configurations and train it by minimizing the Hamiltonian expectation value. This framework enables direct comparison to exact analytic results for a range of key observables, including the ground-state energy, two-point correlators, expectation value of the field, and the structure of the learned wavefunctional itself. Our results provide quantitative diagnostics of accuracy and demonstrate the suitability of momentum space for benchmarking neural network approaches, while establishing a foundation for future extensions to interacting models and position-space formulations.

   hep-phnucl-thPLB(2026)·1 citation
4. 04*

   Analytic Solution for the Helicity Evolution Equations at Small $x$ and Large $N_c\&N_f$

   Jeremy Borden🇺🇸 · Yuri V. Kovchegov🇺🇸

   We construct an exact analytic solution of the revised small-$x$ helicity evolution equations, where the contributions of the quark-to-gluon and gluon-to-quark transition operators were newly included. These evolution equations are written in the large-$N_c\&N_f$ limit and are double-logarithmic, resumming powers of ${\alpha }_s{\ln }^2(1/x)$. Here $N_c$ and $N_f$ are the numbers of quark colors and flavors, while ${\alpha }_s$ is the strong coupling constant and $x$ is the Bjorken-$x$ variable. Using our solution, we obtain analytic expressions for the flavor singlet quark and gluon helicity parton distribution functions (PDFs) and for the $g_1$ structure function as double-inverse Laplace transforms. We also extract analytic expressions for the four DGLAP polarized anomalous dimensions $\Delta {\gamma }_{qq},\Delta {\gamma }_{qG},\Delta {\gamma }_{Gq}$, and $\Delta {\gamma }_{GG}$: these expressions resum powers of ${\alpha }_s/{\omega }^2$ to all orders at large-$N_c\&N_f$ (with $\omega$ the Mellin moment variable). We extract the leading small-$x$ growth of the helicity distributions, \begin{align} \Delta\Sigma(x,Q^2) \sim \Delta G(x,Q^2)\sim g_1(x,Q^2) \sim \left(\frac{1}{x}\right)^{\alpha_h}, \end{align} where the intercept ${\alpha }_h$ satisfies an algebraic equation. We determine ${\alpha }_h$ numerically for various values of $N_c$ and $N_f$. We further obtain the explicit asymptotic expressions for the helicity distributions, which yield numerical values for the ratio of the gluon helicity PDF to the flavor singlet quark helicity PDF in the small-$x$ asymptotic limit (for different $N_f/N_c$). We find that all our predictions for polarized DGLAP anomalous dimensions are fully consistent with the existing finite-order calculations. Similar to the large-$N_c$ case, our intercept ${\alpha }_h$ exhibits a very slight disagreement with the predictions made within the infrared evolution equations framework.

   hep-phnucl-thPRD(2026)·12 citations
5. 05*

   Neutrino magnetic moment in the doublet-singlet Leptoquark model

   Ricardo Sánchez-Vélez🇲🇽

   The transition magnetic moment for Majorana neutrinos is studied in a simple extension of the Standard Model. This extension incorporates two scalar Leptoquarks $S_1$ and ${\tilde{R}}_2$ with quantum numbers $(\bar{3},1,1/3)$ and $(3,2,1/6)$ respectively. It is found that these Leptoquarks generate a sizable transition magnetic moment, particularly when the quark bottom is running in the loop. For our analysis of the parameter space, we include the latest measurement of the muon magnetic moment and combine it with the experimental constraint on the branching ratio Br$(\tau \to \mu \gamma )$. We found that, despite the recent agreement on the $(g-2{)}_{\mu }$ value, large values for Leptoquark Yukawa couplings are allowed due to a degeneracy in the parameters. Additionally, we explore how the Leptoquark model addresses the anomalies observed in the ratios of semileptonic $B$ meson decays, $R_{D^{(\ast )}}$. We determine that the restrictions derived from our analysis are consistent with the most recent experimental limits reported by the XENONnT and LUX-ZEPLIN collaborations. This conclusion is based on our evaluation of the transition magnetic moment from muon neutrino to tau neutrino, focusing on the allowed region for the Leptoquark Yukawa couplings.

   hep-phAdv.High Energy Phys.(2026)·0 citations
6. 06*

   Jet Image Generation in High Energy Physics Using Diffusion Models

   Victor D. Martinez · Vidya Manian🇺🇸 · Sudhir Malik🇺🇸

   This article presents, for the first time, the application of diffusion models for generating jet images corresponding to proton-proton collision events at the Large Hadron Collider (LHC). The kinematic variables of quark, gluon, W-boson, Z-boson, and top quark jets from the JetNet simulation dataset are mapped to two-dimensional image representations. Diffusion models are trained on these images to learn the spatial distribution of jet constituents. We compare the performance of score-based diffusion models and consistency models in accurately generating class-conditional jet images. Unlike approaches based on latent distributions, our method operates directly in image space. The fidelity of the generated images is evaluated using several metrics, including the Fréchet Inception Distance (FID), which demonstrates that consistency models achieve higher fidelity and generation stability compared to score-based diffusion models. These advancements offer significant improvements in computational efficiency and generation accuracy, providing valuable tools for High Energy Physics (HEP) research.

   hep-phcs.AIcs.CVcs.LG0 citations
7. 07*

   Gravitational waves from supermassive right-handed neutrinos produced at preheating

   Shinya Kanemura🇯🇵 · Kunio Kaneta🇯🇵 · Dibyendu Nanda🇯🇵

   The post-inflationary production of supermassive particles can have profound implications for the thermal history of the universe and may leave observable imprints in the gravitational wave (GW) background. In scenarios where the inflaton couples predominantly to heavy fields, say right-handed neutrino (RHN), non-perturbative mechanisms such as parametric resonance can lead to their efficient production, even when their masses exceed the inflaton mass. Once produced, the RHNs emit gravitons through bremsstrahlung as they decay into the Standard Model (SM) particles via $N\to \ell +H$, enabled by the unavoidable minimal coupling to gravity, sourcing a stochastic GW background. We study this mechanism within the framework of $\alpha -$attractor inflationary models, highlighting how the resulting GW spectrum carries indirect imprints of the heavy sector and the post-inflationary dynamics. This offers an observational window into otherwise inaccessible supermassive particles and provides a powerful probe of high-scale physics beyond the SM.

   hep-phastro-ph.COPRD(2026)·7 citations
8. 08*

   Analysis of the hadronic molecules $DK$, $D^{\ast }K$, $D{K}^{\ast }$ and their bottom analogs with QCD sum rules

   Ze Zhou · Guo-Liang Yu · Zhi-Gang Wang · Jie Lu

   In this work, we construct the color-singlet-color-singlet type currents to study the masses and pole residues of charm-strange tetraquark states and their bottom analogs with $J^P$ = $0^{+}$ and $1^{+}$ by using two-point QCD sum rules, where the vacuum condensates are considered up to dimension 12. The predicted masses for $DK$, $D^{\ast }K$ and $D{K}^{\ast }$ molecular states are $2.322_{-0.072}^{+0.066}$ GeV, $2.457_{-0.068}^{+0.064}$ GeV and $2.538_{-0.062}^{+0.059}$ GeV. These results are consistent well with the experimental data of $D_{s0}(2317)$, $D_{s1}(2460)$ and $D_{s1}(2536)$, respectively. The theoretical results for $BK$ and $B^{\ast }K$ molecular states are $5.970_{-0.064}^{+0.061}$ GeV and $6.050_{-0.064}^{+0.062}$ GeV which are all higher than their own thresholds. Finally, the mass of hadronic molecule $B{K}^{\ast }$ is predicted to be $6.158_{-0.063}^{+0.061}$ GeV. This value is lower than the threshold of $B{K}^{\ast }$, which implies that it may be a bound hadronic molecular state.

   hep-phEPJA(2026)·5 citations
9. 09*

   Thermoelectric figure of merit and the deconfinement phase transition

   Kamaljeet Singh🇮🇳 · Raghunath Sahoo🇮🇳

   Thermoelectric phenomena are traditionally associated with the interconversion of thermal and electrical energy in many-body systems. In the context of high-temperature quantum chromodynamics (QCD) matter produced in relativistic heavy-ion collisions, thermoelectric responses can provide insight into the evolving microscopic dynamics and the redistribution of effective degrees of freedom across the phase transition region. In this work, for the first time, we present a phenomenological study of the thermoelectric figure of merit (\( ZT \)) in hot QCD matter, with a particular focus on its behavior across the hadronic and quark-gluon plasma phases. Using model-based calculations for the electrical conductivity, Seebeck coefficient, and thermal conductivity, we analyze the temperature dependence of \( ZT \) and identify characteristic features near the QCD phase transition temperature. Our results indicate that \( ZT \) exhibits nontrivial behavior near the transition region, reflecting the changing transport properties and active degrees of freedom in the medium. This phenomenological study of the thermoelectric figure of merit provides a complementary perspective to traditional transport studies and may provide critical insights for advancing the understanding of QCD matter through the transition region.

   hep-phhep-exhep-thnucl-ex+1PLB(2026)·2 citations
10. 10*

    Rare few-body decays of the Standard Model Higgs boson

    David d'Enterria🇨🇭 · Van Dung Le🇻🇳

    We present a survey of rare and exclusive few-body decays of the standard model (SM) Higgs boson, defined as those into two to four final particles with branching fractions $\mathcal{B}\lesssim 10^{-5}$. Studies of such decays can be exploited to constrain Yukawa couplings of quarks and leptons, probe flavour-changing Higgs decays, estimate backgrounds for exotic Higgs decays into beyond-SM particles, and/or confirm quantum chromodynamics factorization with small nonperturbative corrections. We collect the theoretical $\mathcal{B}$ values for about 70 unobserved Higgs rare decay channels, indicating their current experimental limits, and estimating their expected bounds in p-p collisions at the HL-LHC. Among those, we include 20 new decay channels computed for the first time for ultrarare Higgs boson decays into photons and/or neutrinos, radiative quark-flavour-changing exclusive decays, and radiative decays into leptonium states. This survey can help guide and prioritize upcoming experimental and theoretical studies of unobserved Higgs boson decays.

    hep-phhep-exSciPost Phys.Comm.Rep.(2026)·5 citations
11. 11*

    New Limits on Exotic Muon Interactions Mediated by Axion-Like Particles

    L.Y. Wu🇨🇳 · H. Yan🇨🇳

    The precise measurement of the muon anomalous magnetic moment $a_{\mu }$ provides a sensitive probe of exotic interactions between muons mediated by light beyond the Standard Model (BSM) bosons. Recent advances in both experiment and theory have largely reconciled the long-standing discrepancy in $a_{\mu }$. Using the latest result, $\Delta a_{\mu }=a_{\mu }^{\exp }-a_{\mu }^{\mathrm{SM}}=(38\pm 63)\times 10^{-11}$, we derive updated limits on light BSM boson-mediated exotic muon interactions.

    hep-phastro-ph.HE2 citations
12. 12*

    On multi-propagator angular integrals

    Juliane Haug🇩🇪 · Vladimir A. Smirnov🇷🇺 · Fabian Wunder🇩🇪

    We study multi-propagator angular integrals, a class of phase-space integrals relevant to processes with multiple observed final states and a test-bed for transferring loop-integral technology to phase space integrals without reversed unitarity. We present an Euler integral representation similar to Lee-Pomeransky representation and explicitly describe a recursive IBP reduction and dimensional shift relations for the general case of $n$ denominators. On the level of master integrals, applying a differential equation approach, we explicitly calculate the previously unknown angular integrals with four denominators for any number of masses to finite order in $\epsilon$. Extending the idea of dimensional recurrence, we explore the decomposition of angular integrals into branch integrals reducing the number of scales in the master integrals from $(n+1)n/2$ to $n+1$. To showcase the potential of this method, we calculate the massless three denominator integral to establish all-order results in $\epsilon$ including a resummation of soft logarithms.

    hep-phhep-thJHEP(2025)·3 citations
13. 13*

    The SN 1987A Cooling Bound on Dark Matter Absorption in Electron Targets

    Claudio Andrea Manzari🇺🇸 · Jorge Martin Camalich🇪🇸 · Jonas Spinner🇩🇪 · Robert Ziegler🇩🇪

    We present new supernova (SN 1987A) cooling bounds on sub-MeV fermionic dark matter with effective couplings to electrons. These bounds probe the parameter space relevant for direct detection experiments in which dark matter can be absorbed by the target material, showing strong complementarity with indirect searches and constraints from dark matter overproduction. Crucially, our limits exclude the projected sensitivity regions of current and upcoming direct detection experiments. Since these conclusions are a priori not valid for light mediators, we extend our analysis to this case. We show that sub-GeV mediators can be produced resonantly both in supernova cores and in the early Universe, altering the SN 1987A analysis for effective couplings. Still, a combination of supernova cooling constraints and limits from dark matter overproduction excludes the entire parameter space relevant for direct detection in this case.

    hep-phastro-ph.HEhep-ex2 citations
14. 14*

    Non-Standard Neutrino Interactions at a Muon Collider Neutrino Detector

    Felix Kling🇩🇪 · Yang Ma🇧🇪 · Krzysztof Mękała🇩🇪 · Jürgen Reuter🇩🇪 · Zahra Tabrizi🇺🇸

    In addition to their broad physics reach enabled by their high energies and precision, future multi-TeV muon colliders will also be the world's most intense sources of neutrinos. This offers the opportunity to search for new non-standard neutrino interactions, possible by installing a dedicated forward neutrino detector in the straight sections of the collision ring, which is then used to measure reactions initiated by neutrinos from the decaying beam muons. In this paper, we show that these searches can exceed current and upcoming bounds on non-standard neutrino interactions from low-energy precision experiments and the LHC. This is achieved by the large flux of high-energetic neutrinos, the precise knowledge of the neutrino flavor composition on each side of the interaction point and the chirality of the neutrinos. We further discuss the technical requirements of the proposed forward neutrino detector, \FASERmuC, to maximally exploit this physics potential.

    hep-phhep-exJHEP(2026)·11 citations
15. 15*

    Searching for charged Higgs bosons with flavor-changing couplings at the LHC

    Mohamed Krab🇹🇼

    We investigate the LHC discovery prospects for charged Higgs bosons in the general two Higgs doublet model (G2HDM) that has flavor-changing neutral Higgs (FCNH) couplings. The FCNH ${\rho }_{tc}$ coupling induces intriguing $H^{+}$ production processes $c\bar{b}\to H^{+}$, $cg\to b{H}^{+}$, and $\bar{b}g\to \bar{c}{H}^{+}$ without CKM suppression. Sizable ${\rho }_{tc}$ can drive the disappearance of antimatter from the Universe. In this contribution, we promote the resonant $c\bar{b}\to H^{+}$ production, followed by the bosonic $H^{+}\to W^{+}H$ decay. Discovery could be a harbinger of G2HDM with FCNH couplings, and perhaps shed light on the baryon asymmetry of the Universe.

    hep-phhep-exPoS(2026)·2 citations
16. 16*

    Latin American network on electromagnetic effects in strongly interacting matter: Contribution to the update of the Latin American Strategy for High Energy, Cosmology and Astroparticle Physics

    Ana Mizher🇧🇷 · Alejandro Ayala🇲🇽

    An accurate characterization of the quark-gluon plasma requires understanding of how electromagnetic effects affect the processes mediated by the strong force. All the scenarios in which the plasma emerges, either in nature or in the laboratory, involve strong electromagnetic fields. The early universe, compact astrophysical objects, or ultra-relativistic heavy-ion collisions harbor the most intense fields we know. Researches from the Latin America region have made a substantial contribution on this subject and the \lq\lq Latin American Network on Electromagnetic Effects in Strongly Interacting Matter" aims to cluster efforts to address open questions related to these systems, boosting collaborations and interaction among its members and connecting Latin American institutions with institutions from the rest of the world. In face of the upcoming experimental programs and new facilities, our mission is to bring together experimentalists, phenomenologists and theorists to better explore the properties of strongly interacting matter in the presence of intense electromagnetic fields. This document describes succinctly the recent contributions from researchers of the Latin American region to the subject, as well as our activities and perspectives for the future.

    hep-phhep-exhep-th0 citations
17. 17*

    $\psi (2S)$ production in jets using NRQCD

    Marston Copeland🇺🇸 · Lin Dai🇨🇳 · Yu Fu🇺🇸 · Jyotirmoy Roy🇺🇸

    Based on recent data from LHCb, we study $\psi (2S)$ production in jets using non-relativistic QCD (NRQCD) in conjunction with the Fragmenting Jet Function (FJF) and Gluon Fragmentation Improved Pythia (GFIP) formalisms. Similar to previous studies of $J/\psi$ production in jets, our results show that these formalisms offer a much better description of data than the default Pythia+NRQCD prediction. We compare and contrast the predictions from the FJF formalism and the GFIP approach. In addition, our results show that the distribution of $\psi (2S)$ in jets is an excellent discriminator to test different predictions for the $\psi (2S)$ LDMEs from various extractions. We find a large disparity between the predictions from three different collaborations, showing that a more precise extraction of the $\psi (2S)$ LDMEs may be necessary.

    hep-phnucl-thJHEP(2026)·10 citations
18. 18*

    String-based axial and helicity-flip GPDs: a comparison to lattice QCD

    Florian Hechenberger🇺🇸 · Kiminad A. Mamo🇺🇸 · Ismail Zahed🇺🇸

    We construct an analytic, string based representation of the nucleon's axial and helicity flip conformal moments of generalized parton distributions that holds for any skewness and for both the quark and gluon channels. The starting point is the Mellin Barnes resummation of the conformal partial wave expansion, where the moments are parametrized by open (Reggeon) and closed string (Pomeron) trajectories with slopes determined by experimental form factors and meson/glueball spectroscopy. The forward limits are fixed by the empirical unpolarized and polarized parton distributions. Polynomiality, crossing symmetry and support are satisfied by construction. After NLO DGLAP ERBL evolution to $\mu =2$ GeV our analytic framework (i) reproduces some of the currently available lattice moments of $\mathbb{E}$ and $\tilde{\mathbb{H}}$ in the non singlet sector, (ii) predicts sea quark and gluon polarized moments that will be testable by forthcoming simulations and experiments at Jefferson Lab and the future EIC, and (iii) yields axial and helicity flip GPDs in $x$ space in reasonable agreement with lattice QCD.

    hep-phnucl-thPRD(2025)·7 citations
19. 19*

    On the Edge of Safety: Charge-Charge Correlation in the Back-to-Back Limit

    Pier Francesco Monni🇨🇭 · Gherardo Vita🇨🇭 · Zhen Xu🇨🇳 · Hua Xing Zhu🇨🇳

    We investigate the Charge-Charge Correlation (QQC) in electron-positron annihilation as a probe of charge dynamics in Quantum Chromodynamics. While generally divergent beyond leading order, we show that the QQC is infrared and collinear safe in the back-to-back limit, a property that we dub leading-power safety. This enables an analytic perturbative treatment that bypasses the reliance on non-perturbative track or fragmentation functions. Using Soft-Collinear Effective Field Theory, we derive a factorization theorem and determine its logarithmic behavior analytically up to four loops in QCD, uncovering remarkable connections with the Energy-Energy Correlation (EEC). Prior to this work, the behavior of the QQC beyond leading order was entirely unknown; we now establish its resummation to next-to-next-to-next-to-next-to-leading logarithmic (N${}^4$LL) accuracy, placing it among the observables with the highest perturbative precision alongside the EEC. Our results are validated through a numerical analysis using Event2, exhibiting excellent agreement with the predicted singular terms. This work establishes the QQC as a novel, calculable probe of charge dynamics and unveils a new window into the inner workings of non-Abelian gauge theories.

    hep-phhep-exhep-thPRL(2026)·14 citations
20. 20*

    (Non-)Perturbative Dynamics of a Light QCD Axion: Dark Matter and the Strong CP Problem

    Raymond T. Co🇺🇸 · Taegyu Lee🇺🇸 · Owen P. Leonard🇺🇸

    Considerable theoretical efforts have gone into expanding the reach of the QCD axion beyond its canonical mass--decay-constant relation. The $Z_{\mathcal{N}}$ QCD axion model reduces the QCD axion mass naturally, by invoking a discrete $Z_{\mathcal{N}}$ symmetry through which the axion field is coupled to $\mathcal{N}$ copies of the Standard Model. Before the QCD phase transition at temperature $T_{\mathrm{QCD}}$, the $Z_{\mathcal{N}}$ potential has a minimum at misalignment angle $\theta =\pi$. At $T_{\mathrm{QCD}}$, $\theta =\pi$ becomes a maximum; the axion potential becomes exponentially suppressed and develops $\mathcal{N}$ minima -- only one of which actually solves the strong CP problem. Before $T_{\mathrm{QCD}}$, $\theta$ relaxes towards $\pi$. After $T_{\mathrm{QCD}}$, the axion field starts from around the hilltop and may have sufficient kinetic energy to overcome the newly suppressed potential barriers. Such a field evolution leads to nonlinear effects via the self-interactions near the hilltop, which can cause the exponential growth of fluctuations and backreaction on the coherent motion. This behavior can influence the relic density of the field and the minimum in which it settles. We conduct the first lattice simulations of the $Z_{\mathcal{N}}$ QCD axion using $\mathcal{C}$osmo$\mathcal{L}$attice to accurately calculate dark matter abundances and find nonlinear dynamics reduce the abundance by up to a factor of two. We furthermore find that the probability of solving the strong CP problem tends to diverge considerably from the naive expectation of $1/\mathcal{N}$.

    hep-phastro-ph.COPRD(2025)·7 citations
21. 21*

    Complementary Planetary Spectroscopy Probes of Dark Matter

    Carlos Blanco🇺🇸 · Rebecca K. Leane🇺🇸 · Marianne Moore🇺🇸 · Joshua Tong🇺🇸

    We investigate dark matter (DM) interactions via spectroscopic signatures of energy injection in planetary environments. We develop a general framework to account for how DM energy injection signals depend on the DM spatial distribution, planetary structure, and DM energy deposition profile. We combine UV airglow data on the Solar System's gas giants from the Voyager and New Horizons flybys, and ionospheric measurements from AMS-02 and ELFIN CubeSat on Earth, with internal heat flow data from Cassini, Voyager, and terrestrial boreholes, to constrain DM-nucleon scattering across both heavy and light mediator scenarios. We show that Earth, gas giants, and ice giants probe complementary DM masses and mediator properties, and forecast the reach of a free-floating Super-Jupiter. These results establish planetary spectroscopy as a powerful and versatile probe of the dark sector, complementary to direct detection, cosmology, and collider searches.

    hep-phastro-ph.EPastro-ph.HEPRD(2026)·5 citations
22. 22*

    Angular Coefficients from Interpretable Machine Learning with Symbolic Regression

    Josh Bendavid🇨🇭 · Daniel Conde🇪🇸 · Manuel Morales-Alvarado🇮🇹 · Veronica Sanz🇪🇸 · Maria Ubiali🇬🇧

    We explore the use of symbolic regression to derive compact analytical expressions for angular observables relevant to electroweak boson production at the Large Hadron Collider (LHC). Focusing on the angular coefficients that govern the decay distributions of $W$ and $Z$ bosons, we investigate whether symbolic models can well approximate these quantities, typically computed via computationally costly numerical procedures, with high fidelity and interpretability. Using the PySR package, we first validate the approach in controlled settings, namely in angular distributions in lepton-lepton collisions in QED and in leading-order Drell-Yan production at the LHC. We then apply symbolic regression to extract closed-form expressions for the angular coefficients $A_i$ as functions of transverse momentum, rapidity, and invariant mass, using next-to-leading order simulations of $pp\to {\ell }^{+}{\ell }^{-}$ events. Our results demonstrate that symbolic regression can produce accurate and generalisable expressions that match Monte Carlo predictions within uncertainties, while preserving interpretability and providing insight into the kinematic dependence of angular observables.

    hep-phJHEP(2026)·9 citations
23. 23*

    Cosmic Trajectories calculation with state of the art lattice QCD equation of state

    Lorenzo Formaggio🇺🇸 · Francesco Di Clemente🇺🇸 · Geetika Yadav🇺🇸 · Alessandro Drago🇮🇹 · Claudia Ratti🇺🇸

    We compute the full cosmic trajectories of the early Universe across the QCD phase diagram as the plasma cools from $T\simeq 500$MeV to $30$MeV, assuming $\beta$-equilibrated matter. The trajectories are obtained by simultaneously solving baryon-number, electric-charge, and lepton-asymmetry conservation, closed by a state-of-the-art lattice-QCD equation of state: a fourth-order Taylor expansion in the chemical potentials that merges the latest $(2+1)$-flavor susceptibilities with charm-quark contributions, thus delivering a consistent $(2+1+1)$-flavor equation of state. Results are compared with an ideal quark-gluon plasma and with a hadron-resonance gas to highlight interaction effects. Two cases of primordial lepton asymmetries are analyzed: a symmetric configuration $({\ell }_e={\ell }_{\mu }={\ell }_{\tau }=\ell /3)$ and an asymmetric one $({\ell }_e=0,{\ell }_{\mu }=-{\ell }_{\tau })$. Increasing $|\ell |$ systematically drives the trajectories toward larger values of ${\mu }_B$ and more negative ${\mu }_Q$. In the asymmetric case, a non-monotonic bounce develops when the $\tau$ chemical potential reaches $m_{\tau }$, generating a maximum in ${\mu }_B(T)$, the position of which depends on ${\ell }_{\tau }$. Assuming a modest ${\mu }_Q$-dependence of the lattice-QCD critical end point estimates (obtained at ${\mu }_Q=0$), the trajectories for all lepton asymmetries explored ($|\ell |\lesssim 0.1$) lie to their left, implying that in a standard cosmological scenario the QCD transition is almost certainly a smooth crossover. Nevertheless, we estimate the magnitude of baryon and lepton asymmetries needed to obtain a cosmic trajectory closer to the QCD critical point, providing inputs for future studies of the strong-interaction epoch.

    ↳ astro-ph.COhep-phhep-thPRD(2026)·9 citations
24. 24*

    Eccentricity signatures in LIGO-Virgo-KAGRA's BNS and NSBH binaries

    Keisi Kacanja🇺🇸 · Kanchan Soni🇺🇸 · Alexander Harvey Nitz🇺🇸

    Measurement of eccentricity in low-mass binary systems through gravitational waves is crucial to distinguish between various formation channels. Detecting eccentricity in these systems is challenging due to a lack of accurate eccentric waveform models and the high computational cost of Bayesian inferences. We access the eccentricities of six previously observed low-mass gravitational wave events using publicly available data from the first four observing runs of the LIGO and Virgo collaboration. We analyze the events using the new eccentric waveform model, SEOBNRv5EHM, and compare our results with the existing model, TEOBResumS-Dali. We also present the first eccentricity constraints for GW190814. To improve accuracy, we include higher-order modes in both models and optimize inference using efficient marginalization and parallelization techniques. We find that GW200105 exhibits non-negligible eccentricity, with a measured eccentricity of $e=0.135_{-0.088}^{+0.019}$ at 20 Hz (90% credible level) for TEOBResumS-Dali and $e=0.125_{-0.082}^{+0.029}$ for SEOBNRv5EHM, given a uniform eccentricity prior from 0 to 0.2. This provides moderate support for the eccentric hypothesis, with a Bayes factor of $\sim 6-7$ in favor of the eccentric model. With a uniform log prior on eccentricity, the Bayes factor is reduced to 2.35. The remaining five sources are consistent with low eccentricity, with 90% upper limits from $e\le 0.011$ to $e\le 0.066$. We find no support for non-negligible eccentricity in GW190814. Finally, we discuss the challenges of performing Bayesian inference in eccentric, multi-modal parameter spaces, including issues related to sampling efficiency and waveform systematics.

    ↳ gr-qcastro-ph.HEhep-phPRD(2025)·51 citations
25. 25*

    Implication of neutron star observations to the origin of nucleon mass

    Bikai Gao🇯🇵 · Xiang Liu🇯🇵 · Masayasu Harada🇯🇵 · Yong-Liang Ma🇨🇳

    We investigate the implications of neutron star observations for understanding the origin of nucleon mass using a framework that combines three complementary approaches: the equation of state based on parity doublet structure for hadronic matter below $2n_0$, the Nambu-Jona-Lasinio (NJL) model for quark matter above $5n_0$, and a model-independent analysis of the intermediate density region based on fundamental physical principles. By systematically exploring parameter spaces and comparing theoretical predictions with recent observational constraints, we establish constraints on the chiral invariant mass. Our results suggest that more than a half of the nucleon mass originates from sources beyond spontaneous chiral symmetry breaking, challenging conventional understanding of nucleon mass generation. These constraints arise solely from fundamental physical principles and observational data, independent of specific assumptions about the nature of the quark-hadron transition, providing robust insights into the microscopic origin of hadron masses.

    ↳ nucl-thastro-ph.HEastro-ph.SRhep-ph+1SCPMA(2026)·9 citations
26. 26*

    Coupled-channel contributions to the GDH sum rule from the Jülich-Bonn approach

    Carolin Schneider🇩🇪 · Deborah Rönchen🇩🇪 · Christoph Hanhart🇩🇪 · Ulf-G. Meißner🇩🇪

    We study the Gerasimov-Drell-Hearn (GDH) sum rule within a dynamical coupled-channel approach, the Jülich-Bonn model for light baryon resonances based on fits to an extensive data base of pion and photon induced data. Recently published photoproduction data for different observables with $\pi N$ and $\eta N$ final states are analyzed simultaneously with older data for the reactions $\pi N\to \pi N$, $\eta N$, $K\Lambda$, $K\Sigma$ and $\gamma p\to \pi N$, $\eta N$, $K\Lambda$, $K\Sigma$. The impact of the new data on the resonance spectrum is investigated and the contribution of the individual channels to the GDH integral is determined.

    ↳ nucl-thhep-phnucl-exEPJA(2025)·2 citations
27. 27*

    The Mass of the Baryon Junction: a lattice computation in 2 +1 dimensions

    Michele Caselle🇮🇹 · Nicodemo Magnoli🇮🇹 · Dario Panfalone🇮🇹 · Lorenzo Verzichelli🇮🇹

    We present a systematic study of baryonic flux tubes in SU(3) Yang-Mills theory in (2+1) dimensions. A recent next-to-leading-order derivation within the Effective String Theory framework has, for the first time, made explicit the corrections proportional to the mass of the baryon junction M, up to order $1/R^2$ (where $R$ is the length of the confining strings), opening the possibility of its non-perturbative determination. One of the main goals of this paper is, through high precision simulations of the three-point Polyakov loop correlator, to measure for the first time the baryon junction mass. By isolating the predicted $1/R^2$ term in the open string channel, we obtain the value $M/\sqrt{\sigma }=0.1355(36)$, similar to the phenomenological value which is used to describe hadrons, although our computation was done in (2+1) dimensions. In addition, studying the high temperature behavior of the baryon, we present a new test of the Svetitsky-Yaffe conjecture for the SU(3) theory in three dimensions. Focusing on the high temperature regime, just below the deconfinement transition, we compare our lattice results for Polyakov loop correlators with the quantitative predictions obtained by applying conformal perturbation theory to the three-state Potts model in two dimensions and find excellent agreement.

    ↳ hep-lathep-phhep-thJHEP(2025)·6 citations
28. 28*

    Fermion selective tests of new physics with the bound electron g-factor

    Matteo Moretti🇩🇪 · Christoph H. Keitel🇩🇪 · Zoltán Harman🇩🇪

    The use of high-precision measurements of the $g$ factor of single-electron ions is considered as a detailed probe for physics beyond the Standard Model. The contribution of the exchange of a hypothetical force-carrying scalar boson to the $g$ factor is calculated for the ground state of H-like ions and used to derive bounds on the parameters of that force. Similarly to the isotope shift, we employ the nuclide shift, i.e. the difference for elements with different proton and/or neutron numbers, in order to increase the experimental sensitivity to the new physics contribution. In particular we find, combining available measurements with current precision with different ions, that the coupling constant for the interaction between an electron and a proton can be constrained up to three orders of magnitude better than with the best current atomic data and theory.

    ↳ physics.atom-phhep-phPRL(2026)·3 citations
29. 29*

    Forward cascade of large-scale primordial magnetic fields during structure formation

    Molly Abramson · Emma Clarke🇺🇸 · Tina Kahniashvili🇺🇸 · Sayan Mandal🇺🇸 · Salome Mtchedlidze · Jennifer Schober🇨🇭

    The origin of large scale magnetic fields in the Universe is widely thought to be from early Universe processes, like inflation or phase transitions. These magnetic fields evolve via magnetohydrodynamic processes until the epoch of recombination. When structures begin to form in the later Universe, the conservation of magnetic flux amplifies the magnetic fields via the adiabatic collapse of gravitationally bound gas clouds hosting the magnetic fields and moves them to smaller scales. In this work, we have semi-analytically studied this forward cascade effect, considering simple models of gravitational collapse of structures. We find that this simple model is able to reproduce the general qualitative features of the evolution of the magnetic field spectrum as seen from magnetized cosmological simulations.

    ↳ astro-ph.COastro-ph.GAhep-phPRD(2026)·2 citations
30. 30*

    Gravitational waves from axion inflation in the gradient expansion formalism. Part I. Pure axion inflation

    Richard von Eckardstein🇩🇪 · Kai Schmitz🇩🇪 · Oleksandr Sobol🇩🇪

    Axion inflation is a well-motivated model of cosmic inflation with a rich phenomenology. The abundant production of gauge fields during axion inflation notably sources a stochastic gravitational-wave (GW) background signal, which nourishes the hope that future GW searches might have a chance to probe the model. In this paper, we scrutinize GW production during axion inflation in the gradient expansion formalism (GEF), a powerful numerical technique that captures the nonlinear dynamics of the system in the limit of vanishing axion gradients. We focus on {single-field} axion inflation coupled to a pure Abelian gauge sector, i.e., pure axion inflation (PAI), and perform the first-ever {detailed} parameter scan of GW production in the Abelian PAI model close to the onset of strong backreaction. {We approximate the axion potential around its minimum by a quadratic mass term and study the tensor modes that exit the Hubble horizon as the axion rolls down this potential.} Remarkably enough, we find that GW signals within the reach of future GW interferometers can only be realized in parameter regions that also lead to strong backreaction and that are in conflict with the upper limit on $\Delta N_{\mathrm{eff}}$, i.e., the allowed energy density of dark radiation. This observation defines a clear target for future lattice studies of axion inflation that may confirm or improve the predictions of our GEF benchmark.

    ↳ astro-ph.COgr-qchep-phJHEP(2026)·14 citations
31. 31*

    Gauge symmetry and radiatively induced terms in dimension-5 non-minimal Lorentz-violating QED

    A. P. B. Scarpelli🇧🇷 · A. R. Vieira🇧🇷

    In this work, we derive the conditions that assure gauge invariance of a non-minimal dimension-5 Lorentz-violating QED. The two and three point functions at one-loop are computed. The gauge Ward identities are checked and the conditions to assure gauge symmetry of this non-minimal framework is found to be the same of the usual QED. Induced terms are also investigated and it is shown that the non-minimal Lorentz-violating $a_F^{(5)}$-term of the fermion sector can induce radiatively a non-minimal Lorentz-violating term in the photon sector.

    ↳ hep-thhep-phUniverse(2025)·0 citations
32. 32*

    Search for Dark Matter Scattering from Optically Levitated Nanoparticles

    Yu-Han Tseng🇺🇸 · T. W. Penny🇺🇸 · Benjamin Siegel🇺🇸 · Jiaxiang Wang🇺🇸 · David C. Moore🇺🇸

    The development of levitated optomechanics has enabled precise force sensors that operate in the quantum measurement regime, opening up unique opportunities to search for new physics whose weak interactions may have evaded existing sensors. We demonstrate the detection of impulsive forces acting on optically levitated nanoparticles, where the dominant noise source is provided by measurement backaction. Using these sensors, we search for momentum transfers that may originate from scattering of passing particlelike dark matter. For dark matter that couples to Standard Model neutrons via a generic long-range interaction, this search constrains a range of models in the mass range $1$-$10^{7}GeV/c^2$, placing upper limits on single neutron coupling strength as low as $\le 1\times 10^{-7}$ at the 95% confidence level. We also demonstrate the ability of using the inherent directional sensitivity of these sensors to separate possible dark matter signals from backgrounds. Future extensions of the techniques developed here can enable searches for light dark matter and massive neutrinos that can reach sensitivity several orders of magnitude beyond existing searches.

    ↳ hep-exhep-phquant-phPRX Quantum(2025)·17 citations
33. 33*

    Categorical Anomaly Matching

    Andrea Antinucci🇬🇧 · Christian Copetti🇬🇧 · Yuhan Gai🇬🇧 · Sakura Schafer-Nameki🇬🇧

    Matching 't Hooft anomalies is a powerful tool for constraining the low-energy dynamics of quantum systems and their allowed renormalization group (RG) flows. For non-invertible (or categorical) symmetries, however, a key challenge has been the lack of a precise framework to characterize and quantify anomalies. We address this by identifying tensor functors between UV and IR symmetry categories as central to capturing these constraints. To this end, we introduce Anomalous Simple Categories (ASCies) as fundamental building blocks of categorical anomalies. A given symmetry category may support multiple ASCies, each encoding distinct anomalous features. These structures naturally arise in the context of the Symmetry Topological Field Theory (SymTFT), where tensor functors correspond to RG-interfaces between UV and IR SymTFTs, and ASCies are realized as particular such interfaces satisfying simple, universal criteria. We demonstrate the utility of this framework through examples involving anomalous 0-form, higher-form, and crucially, non-invertible symmetries in various spacetime dimensions.

    ↳ hep-thcond-mat.str-elhep-phmath.CT20 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.