Wed·Mar 25, 2026Wednesday·March 25, 2026

1. 01*

   Light-by-light scattering at three loops in massless QCD and QED: amplitudes and cross sections

   Piotr Bargiela🇬🇧 · Amlan Chakraborty🇮🇹 · Giulio Gambuti🇨🇭 · Melih A. Ozcelik🇫🇷

   We present the calculation of three-loop massless QCD and QED helicity amplitudes for light-by-light scattering. We make use of Lorentz tensor decomposition in the 't Hooft-Veltman dimensional regularisation scheme to reduce the complexity of the computation. Our analytic amplitude results are remarkably compact and can be efficiently evaluated numerically. We employ them to compute the corresponding NNLO differential cross-section predictions in the invariant mass and rapidity distributions of the di-photon system, for which we find agreement with the experimental ATLAS data from ultra-peripheral heavy-ion collisions.

   hep-phhep-th3 citations
2. 02*

   Analyzing Fermionic Dark Matter scenarios with anomalous compact objects

   Yaiza Cano🇪🇸 · Jose Manuel Alarcón🇪🇸

   In this paper, we consider three compact objects (HESS J1731-347, PSR J1231-1411, XTE J1814-338) with anomalous mass-radius relation to analyze the possibility of being dark matter admixed neutron stars. We try to infer the dark matter particle properties, under the assumption of behaving as a free Fermi gas. The main novelty relies on the use of a baryonic equation of state obtained from first principles in the whole density range, that allows to eliminate the model dependence of the baryonic part of the calculation. Once the possible Dark Matter Admixed Neutron Star configurations are obtained, we check their stability and whether it is feasible for a Neutron Star to capture the necessary dark matter fraction. We show that two of the anomalous compact objects (HESS J1731-347 and PSR J1231-1411) can be explained with a small fraction of fermionic dark matter content in the star. The other compact object (XTE J1814-338) cannot be explained as a dark matter admixed neutron star, and becomes a potential candidate for a twin star.

   hep-phastro-ph.HEnucl-th2 citations
3. 03*

   Pseudoscalar contributions to Zh production at the LHC at 95 GeV and above

   J. Dutta🇮🇳 · P. M. Ferreira🇵🇹 · S. Heinemeyer🇪🇸

   In generalizations of the Standard Models with extended scalar sectors, pseudoscalar particles will contribute to associated production of the Higgs boson discovered at the LHC, $h$, and the $Z$ boson. The pseudoscalar can be produced via gluon-gluon fusion, and as such may give contributions to $Zh$ production comparable to the value predicted by the Standard Model. We analyze this possibility in two different models, the Two Higgs Doublet Model, with and without an added complex singlet scalar, computing both the total and differential cross sections for this process. We focus on two pseudoscalar mass regions: (i) $m_A\sim 95$ GeV, to describe the di-photon excesses observed by CMS and ATLAS; (ii) 100 GeV $\le m_A\le$ 1000 GeV, as a generic heavier pseudoscalar. A pseudoscalar with $m_A\sim 95$ GeV tends to give a contribution to the $pp\to Zh$ cross section that is too small to set new limits on the parameter spaces of the two models. Heavier pseudoscalars, on the other hand, can yield cross-section contributions larger than allowed by current LHC measurements and thus restricting regions of parameter space of these models which are in agreement with theoretical and all other experimental constraints. The increase of LHC luminosity will yield even substantially tighter constraints.

   hep-ph1 citation
4. 04*

   The FERMIACC: Agents for Particle Theory

   Prateek Agrawal🇺🇸 · Nathaniel Craig🇺🇸 · Amalia Madden🇺🇸 · Iñigo Valenzuela Lombera🇺🇸

   We present the FERMIACC, a scaffolded reasoning model built on OpenAI agents designed to autonomously generate and quantitatively validate theory hypotheses for high energy physics data at scale.

   hep-ph19 citations
5. 05*

   Dynamically assisted Schwinger pair production in differently polarized electric fields with the frequency chirping

   Abhinav Jangir🇮🇳 · Anees Ahmed🇮🇳

   We investigate the enhanced dynamically assisted electron-positron pair production in differently polarized electric fields with frequency chirps within the real-time Dirac-Heisenberg-Wigner formalism. The combined influence of the chirp strength and the field polarization on the momentum distribution and the total number density of the created pairs is studied in detail for one-color fields as well as dynamically assisted two-color combined fields. Frequency chirps, applied in different field configurations, strongly reshape the momentum spectra by modifying the interference patterns and enhancing the peak momentum distribution. In the dynamically assisted case, the total number density can be enhanced significantly over $2-3$ orders when large chirps are applied to both strong and weak fields. Furthermore, we observe that sensitivity of the number density to field polarization progressively diminishes as the chirp strength increases, a trend that holds for both one-color field and the assisted two-color combined fields. A comparison of different chirping scenarios shows that chirping only the weak field produces nearly the same enhancement in the pair yield as chirping both fields simultaneously, demonstrating that the weak-field chirp plays the dominant role in the chirp-induced enhancement of the dynamically assisted Schwinger mechanism. We also find the enhancement factor to be the largest near circular polarization in the chirp-free and weakly chirped regimes, but is strongly suppressed with increasing weak-field chirp despite the continued growth of the absolute pair yield. These results provide new insight into the interplay among chirp, polarization, and dynamical assistance in strong-field quantum electrodynamics.

   hep-phhep-thPRD(2026)·0 citations
6. 06*

   Dark graviton sensing with magnetically levitated superconductors

   Valentina Danieli🇨🇿 · Paola C. M. Delgado🇨🇿 · Federico R. Urban🇨🇿

   Levitated sensors have emerged as a new frontier to detect ultra-light dark matter such as axion-like particles and dark photons. In this work we study how a magnetically levitated superconductor responds to a spin-2 dark matter field, the dark graviton, in the dHz to kHz frequency range. To do so, we compute the forces that the dark graviton exerts on the superconductor, separately for matter and light couplings. The matter coupling produces a strain-like tidal acceleration between the superconductor and the readout pick-up loop in a way that is akin to a slow, continuous, massive gravitational wave. The light coupling instead induces an effective current that sources an oscillating magnetic field, thus driving the superdiamagnetic response of the superconductor. We find that, even with significant experimental improvements, the sensitivity reach for the matter coupling is not competitive with existing interferometers or fifth-force experiments. On the other hand, magnetically levitated superconductors could be among the most sensitive laboratory probes of the dark-graviton coupling to electromagnetism, especially at low frequencies, provided technical and readout noise can be kept under control.

   hep-phastro-ph.COgr-qchep-ex2 citations
7. 07*

   A search for heavy axion-like particles in light-by-light scattering at the FCC-hh

   S.C. Inan🇹🇷 · A.V. Kisselev🇷🇺

   A virtual production of heavy axion-like particles (ALPs) via light-by-light scattering in pp, pPb and Pb collisions at the future 100 TeV collider FCC-hh is studied. Both differential and total cross sections are calculated. The 95\% C.L. exclusion limits, as well as $3\sigma$ and $5\sigma$ discovery limits on an ALP coupling constant versus ALP mass $m_a$ are given, using integrated luminosities of 30 ab${}^{-1}$, 27 pb${}^{-1}$ and 110 nb${}^{-1}$. Our results are compared with the current LHC bounds. The strongest limit on the ALP coupling is obtained if $m_a\simeq 250$ GeV for the PbPb collisions, and if $m_a\simeq 1$ TeV for pp or pPb collisions. This suggests that the FCC-hh has a great physics potential of searching for the heavy ALPs.

   hep-phhep-exJHEP(2026)·0 citations
8. 08*

   Transition form factors for $D/B$ to $a_0(980)$ from light-cone QCD sum rules

   Di Gao🇨🇳 · Jiangshan Lan🇨🇳 · Duojie Jia🇨🇳 · Xingbo Zhao🇨🇳 · Yanjun Sun🇨🇳

   We apply the light-cone QCD sum rules with chiral currents to compute transition form factors of the semileptonic decay of the charmed and bottom scalar mesons $D/B$ to $a_0(980)l^{+}{\nu }_l$ $(l=e$, $\mu )$, where the scalar meson $a_0(980)$ are firstly regarded as two quark states, and contributions from the tetraquark component are then added via proper modulation of four distribution amplitudes considered. The obtained transition form factors and branching fraction are free of the contribution from the light-cone distribution amplitudes at the level of twist-three and two simple relations connecting their form factors are obtained. Our computations indicates that the decay branch fractions are on the margin of the measurements reported by Beijing Spectrometer \uppercase\expandafter{\romannumeral3} in the pure two-quark scenario and are in good agreement with observations when tetraquark component is considered.

   hep-phPRD(2026)·0 citations
9. 09*

   Gravitational Waves from Mergers of Asymmetric Dark Stars

   Boris Betancourt Kamenetskaia🇰🇷 · Qianhang Ding🇰🇷 · Chris Kouvaris🇬🇷

   A strongly self-interacting component of asymmetric dark matter (DM) particles can form compact dark stars (DSs). These objects have a broad spectrum of masses and radii, with distinct evolution histories from both neutron stars and black holes (BHs). We argue that these differences allow a population of DSs to contribute significantly to the astrophysical merger rate in unique and discernible ways. Specifically, their merger rate could dominate at low redshifts over other sources, while their mass function may populate windows outside known astrophysical processes. We investigate the structure and formation of DSs within a dissipative model, and calculate the enhancement of their merger cross-section due to tidal deformation effects. From this, we derive the present-day merger rate and its differential mass distribution. These findings open a new window to probe DM substructure and particle interactions through present and future gravitational wave (GW) observatories.

   hep-ph1 citation
10. 10*

    Relativistic quantum mechanics of massive neutrinos in a rotating frame

    Alexander Breev🇷🇺 · Maxim Dvornikov🇷🇺

    We study the evolution of neutrinos electroweakly interacting with a rotating matter. The description of neutrinos is based on the Dirac equation in the corotating noninertial frame where matter is at rest. We find solution of this Dirac equation, where the matter angular velocity is accounted for exactly, for massless neutrinos. In case of massive particles, this solution is obtained for a slowly rotating matter. Our findings are compared with previous research. We consider two applications of our results. First, we compute the electroweak contribution to the vector current of neutrinos along the rotation axis, which is analogous to the chiral vortical effect. This current is shown to be nonzero for both massless and massive particles. Then, we take into account the nonzero mixing between different mass eigenstates. It allows us to study neutrino flavor oscillations in rotating matter and account for noninertial effects. We derive the transition probability which reveals the resonance. These findings generalize the description of neutrino oscillations in a nonmoving matter. Some astrophysical applications are briefly discussed.

    hep-phhep-thPRD(2026)·0 citations
11. 11*

    Cosmic Ray Boosted Dark Matter in COSINUS: Modeling and Constraints

    G. Angloher🇩🇪 · M. R. Bharadwaj🇩🇪 · A. Böhmer🇦🇹 · M. Cababie🇦🇹 · I. Colantoni🇮🇹 · I. Dafinei🇮🇹 · N. Di Marco🇮🇹 · C. Dittmar🇩🇪 · F. Ferella🇮🇹 · F. Ferroni🇮🇹 · S. Fichtinger🇦🇹 · A. Filipponi🇮🇹 and 32 other authors

    Direct detection of nuclear recoils due to sub-GeV dark matter is challenging because of the small kinetic energy of the light dark matter particles. Although limits down to a few hundred MeV have been reached using specially designed low threshold detectors, further improvements are now constrained more by background event rates than by energy thresholds. However, constraints down to sub-MeV dark matter masses can still be obtained through the boosted dark matter framework. In this scenario, high-energy cosmic rays or neutrinos scatter off dark matter particles, imparting additional kinetic energy and boosting them beyond the typical velocities expected from the non-relativistic dark matter halo. These boosted dark matter particles can then be detected even by experiments with higher energy thresholds. In this work, we present a catalog of dark matter - nucleon scattering cross sections corresponding to a heavy mediator limit for spin zero, one half and one dark matter and for scalar and vector mediators with even or odd parity. Based on these results, we present projected constraints on the dark matter - nucleon cross section for the COSINUS experiment, assuming an exposure of 100 kg d, demonstrating the potential sensitivity to sub-GeV boosted dark matter.

    hep-phastro-ph.COhep-ex1 citation
12. 12*

    Pion and Kaon Fragmentation Functions from Continuum Schwinger Function Methods

    Hui-Yu Xing🇨🇳

    Using the Drell-Levy-Yan relation, the pion and kaon elementary fragmentation functions (EFFs) are obtained from their hadron-scale parton distribution functions (DFs). These EFFs serve as driving terms in the hadron cascade equations, whose solution yields the complete array of hadron-scale fragmentation functions (FFs) for pion and kaon production in high energy reactions. Evolved to experimental scales, the continuum Schwinger function methods (CSMs) predictions satisfy QCD endpoint behavior: nonsinglet FFs vanish at $z=0$, singlet FFs diverge faster than $1/z$. Jet multiplicity predictions reveal SU(3) symmetry breaking in the charged/neutral kaon ratio, decreasing with energy, and show the pion/kaon ratio in $e^{+}{e}^{-}$ collisions asymptotes to a mass-independent value.

    hep-ph0 citations
13. 13*

    Light fermionic dark matter window in the scotogenic inverse seesaw model

    Huan-Can Liang🇨🇳 · Yi Liao🇨🇳 · Xiao-Dong Ma🇨🇳 · Mu-Yuan Song🇨🇳 · Hao-Lin Wang🇨🇳

    The origin of neutrino mass and the nature of dark matter (DM) remain unresolved puzzles in particle physics, and an appealing possibility is to address both in a unified picture. This paper explores a light fermionic DM candidate within the scotogenic inverse seesaw model, which can simultaneously provide a mechanism for neutrino mass generation. By incorporating constraints from neutrino oscillation data, charged lepton flavor violating processes, invisible decays of the Higgs and $Z$ bosons, DM relic density, and direct detection of DM, we uncover a light fermionic DM window in the mass range $58\mathrm{GeV}\lesssim m_{\mathtt{DM}}\lesssim 63\mathrm{GeV}$ that can satisfy all of the aforementioned constraints. We find that this window can be jointly tested by next-generation ton-scale DM direct detection experiments including PandaX-xT and XENONnT, Higgs invisible decays, and future lepton colliders such as ILC.

    hep-ph0 citations
14. 14*

    Unified description of Sivers and Boer-Mulders asymmetries from twist-3 correlations

    Zhimin Zhu · Jiangshan Lan · Chandan Mondal · Xingbo Zhao · James P. Vary · BLFQ Collaboration

    We present the first calculation of the Efremov-Teryaev-Qiu-Sterman functions and associated twist-3 quark-gluon correlation functions for both the proton and pion. These functions are determined using the light-front wave functions obtained by diagonalizing a light-front effective Hamiltonian within a Fock space truncated to include a dynamical gluon. We compute the twist-3 correlations in the hard-pole region and extrapolate them to the soft-gluon pole limit. After the scale evolutions, our predictions demonstrate quantitative consistency with recent experimental extractions, providing a unified description of the Sivers and Boer-Mulders asymmetries from a light-front Hamiltonian approach.

    hep-phhep-thnucl-th1 citation
15. 15*

    Leptogenesis implications of two-zero textures of Majorana neutrino mass matrix in type-I seesaw model

    Xin-Tong Ma🇨🇳 · Ding-Hui Xu🇨🇳 · Zhen-hua Zhao🇨🇳

    The type-I seesaw model with two-zero textures of the Majorana mass matrix for the right-handed neutrinos $M_{\mathrm{R}}^{}$ provides a highly predictive framework for neutrino mass generation and baryon asymmetry of the Universe via leptogenesis. In this work, we systematically investigate the compatibility of viable two-zero textures of $M_{\mathrm{R}}^{}$ with leptogenesis within the type-I seesaw scenario. We consider both a general diagonal Dirac neutrino mass matrix $M_{\mathrm{D}}^{}$ and two theoretically motivated special cases, namely the SO(10) GUT-inspired $M_{\mathrm{D}}^{}\sim \mathrm{diag}(m_u,m_c,m_t)$ and the flavor symmetry-induced $M_{\mathrm{D}}^{}\propto I$. Our study shows that two-zero textures of $M_{\mathrm{R}}^{}$ yield strong correlations between neutrino parameters and leptogenesis, offering distinctive phenomenological implications for neutrino flavor physics and baryon asymmetry of the Universe.

    hep-ph0 citations
16. 16*

    Soft Symmetry Breaking as a Nonstandard Source of Mass: Phenomenological Insights from the Two-Higgs-Doublet Model

    Dipankar Das🇮🇳 · Miguel Levy🇨🇭 · Shreya Pandey🇮🇳 · Ipsita Saha🇮🇳 · Agnivo Sarkar🇮🇳

    The soft-breaking parameter, $m_{12}^2$, frequently appearing in the 2HDM scalar potential is much more remarkable than being just a nonstandard parameter that helps make the BSM scalars super heavy. In fact, as we show through explicit calculations, it should be treated as the direct but concise embodiment of new non-electroweak spontaneous symmetry breaking effects at very high energy scales, wherein lies its quiddities. Consequently, it is argued that $m_{12}^2$ and the electroweak VEV serve as two distinct sources for the nonstandard scalar masses, which are completely unrelated to each other. Such distinctions allow us to define parameters that conveniently capture the fraction of the nonstandard scalar masses derived from the electroweak VEV. Finally, we demonstrate that constraints can already be placed on such fractions from the current measurements of the diphoton signal strength and from direct searches of new nonstandard scalar resonances in the diphoton channel.

    hep-ph0 citations
17. 17*

    Five-flavor molecular pentaquarks in the ${\Xi }_b^{(\prime ,\ast )}{\bar{D}}^{(\ast )}$ and ${\Xi }_c^{(\prime ,\ast )}{B}^{(\ast )}$ systems

    Fu-Lai Wang🇨🇳 · Xiang Liu🇨🇳

    The discovery of hidden-charm pentaquarks and open-flavor tetraquarks motivates the search for even more exotic hadron configurations. In this work, we investigate genuinely exotic molecular pentaquark candidates comprising five different flavors, focusing on the ${\Xi }_b^{(\prime ,\ast )}{\bar{D}}^{(\ast )}$ and ${\Xi }_c^{(\prime ,\ast )}{B}^{(\ast )}$ systems. Employing the one-boson-exchange model with the $S$-$D$ wave mixing and coupled-channel dynamics, we identify the most promising molecular pentaquark candidates comprising five different flavors. These include the ${\Xi }_b\bar{D}$, ${\Xi }_b^{\prime }\bar{D}$, ${\Xi }_{c}B$, and ${\Xi }_c^{\prime }B$ states with $I(J^P)=0(1/2^{-})$, the ${\Xi }_b{\bar{D}}^{\ast }$, ${\Xi }_b^{\prime }{\bar{D}}^{\ast }$, ${\Xi }_c{B}^{\ast }$, and ${\Xi }_c^{\prime }{B}^{\ast }$ states with $I(J^P)=0(1/2^{-},3/2^{-})$, the ${\Xi }_b^{\ast }\bar{D}$ and ${\Xi }_c^{\ast }B$ states with $I(J^P)=0(3/2^{-})$, as well as the ${\Xi }_b^{\ast }{\bar{D}}^{\ast }$ and ${\Xi }_c^{\ast }{B}^{\ast }$ states with $I(J^P)=0(1/2^{-},3/2^{-},5/2^{-})$. Importantly, these loosely bound states exhibit pronounced spin splittings across different total angular momentum configurations after incorporating the spin-dependent interactions or the channel couplings. In addition, we identify several possible isovector molecular pentaquark candidates within the ${\Xi }_b^{(\prime ,\ast )}{\bar{D}}^{(\ast )}$ and ${\Xi }_c^{(\prime ,\ast )}{B}^{(\ast )}$ systems. Our predictions provide clear targets for experimental searches at facilities such as LHCb and Belle II, where the unique five-flavor quark configuration offers a distinctive experimental signature.

    hep-phhep-exPRD(2026)·3 citations
18. 18*

    Dark Matter Detection through Rydberg Atom Transducer

    J. F. Chen🇨🇳 · Haokun Fu🇨🇳 · Christina Gao🇨🇳 · Jing Shu🇨🇳 · Geng-Bo Wu🇨🇳 · Peiran Yin🇨🇳 · Yi-Ming Zhong🇨🇳 · Ying Zuo🇨🇳

    Ultralight bosonic dark matter with masses in the meV range, corresponding to terahertz (THz) Compton frequencies, remains largely unexplored due to the difficulty of achieving both efficient signal conversion and single-photon-sensitive detection at THz frequencies. We propose a hybrid detection architecture that integrates a dielectric haloscope, Rydberg-atom transducer, and superconducting nanowire single-photon detection within a unified cryogenic platform operating at $\lesssim 1\text{K}$. The dielectric haloscope converts dark matter into THz photons via phase-matched resonant enhancement, achieving form factors $C\sim 0.4$ and loaded quality factors $Q_L\sim 10^4$. A cold ${}^{87}$Rb ensemble then coherently up-converts the THz signal to the optical domain through six-wave mixing among Rydberg states. The intrinsic directionality and narrow bandwidth ($\Delta {\nu }_{\mathrm{atomic}}\sim 1\text{MHz}$) of this process provide extra suppression of isotropic thermal backgrounds. With 10 days of integration at $0.3\text{K}$, we project sensitivity to the axion-photon coupling $g_{a\gamma \gamma }\sim 10^{-13}{\mathrm{GeV}}^{-1}$ at $m_a\sim 0.4\text{meV}$, reaching the QCD axion band and opening the THz window for searches of both axion and dark photon dark matter.

    hep-phastro-ph.COhep-exphysics.atom-ph+11 citation
19. 19*

    Gravity tidings from domain walls: Flavour hierarchies are making waves

    Stefan Antusch🇨🇭 · Ivo de Medeiros Varzielas🇵🇹 · Miguel Levy🇨🇭

    Explaining the observed charged fermion mass hierarchies points to flavour symmetries inducing a suppression of the lighter species' masses. When the symmetries are global, it is expected that such symmetries are broken by gravity via Planck scale suppressed effective operators. The potential of the spontaneous symmetry-breaking "flavon" field, if the symmetry is discrete, then possesses several minima, with the vacuum-degeneracy lifted by the gravity effects. In such scenarios, domain walls might be generated in the process of symmetry breaking. Due to the bias, however, they potentially annihilate sufficiently before Big Bang nucleosynthesis, avoiding conflict with observations and generating a characteristic contribution to the stochastic gravitational wave background. We discuss whether and how minimalistic supersymmetric and non-supersymmetric realisations of such theories can give rise to observable gravitational waves.

    hep-ph2 citations
20. 20*

    Sub-eikonal Structure of High-Energy Deep-Inelastic Scattering

    Giovanni Antonio Chirilli🇵🇱

    I develop a mixed-space formulation of high-energy deep-inelastic scattering in the shock-wave formalism at sub-eikonal order. Starting from the quark propagator in the background field, I derive the corresponding mixed-space Feynman rules from the LSZ reduction formula in the presence of a shock wave, including the instantaneous contributions generated by the presence of the shock-wave. As a first check of the formalism, I rederive the standard eikonal dipole cross sections for longitudinal and transverse photon polarization. I then use the same framework to compute the first sub-eikonal corrections to the dipole structure functions. In particular, I obtain the sub-eikonal contributions to the longitudinal and transverse structure functions $F_L$ and $F_T$, as well as to the helicity-sensitive asymmetry related to $g_1$, and organize the result in terms of a gauge-invariant operator basis. The resulting operator combinations are naturally written in dipole form and vanish in the zero-dipole-size limit, making the unitarity property and the small-dipole behavior manifest. Finally, I analyze the divergence structure of the sub-eikonal dipole corrections. I show that the longitudinal structure function is finite at this order, whereas the transverse and helicity-dependent structure functions contain only logarithmic divergences.

    hep-ph6 citations
21. 21*

    Magnetic moments of decuplet baryons in asymmetric magnetized nuclear matter

    Utsa Dastidar🇮🇳 · Arvind Kumar🇮🇳 · Harleen Dahiya🇮🇳 · Suneel Dutt🇮🇳

    Understanding the novel QCD phenomenon under high external magnetic fields of hot and dense medium help us to develop a better understanding of the underlying quark dynamics of baryons. Using a hybrid approach based on the effective field theory that treats quarks as the fundamental degrees of freedom and calculating the individual contribution of valence, sea and orbital angular moment of sea quark, the magnetic moment of a given baryon of the decuplet family is calculated. The incorporation of Landau quantization in the vector and scalar densities of baryons help us to obtain the impact of external magnetic field on the properties of baryons within the chiral SU(3) quark mean field model (CQMF). In the present study, effective masses of the baryons are calculated using CQMF while the framework of chiral constituent quark model ($\chi$CQM), extended to SU(4) sector, is used to obtain the effective magnetic moments of decuplet baryons under the influence of magnetic field.

    hep-ph1 citation
22. 22*

    Assessing boundedness from below in the ${\mathbb{Z}}_2\times {\mathbb{Z}}_2$-symmetric three-Higgs-doublet model: algorithm and machine learning

    Darius Jurčiukonis🇱🇹 · Luís Lavoura🇵🇹 · André Milagre🇵🇹

    The scalar potential of any particle-physics model must be bounded from below (BFB). We consider the extension of the Standard electroweak Model with three $SU(2)$ doublets of scalars and a symmetry under which each of those doublets changes sign. In the absence of necessary and sufficient conditions for boundedness from below (BnessFB) for this specific model, we argue that one may use increasingly stringent sets of necessary conditions. We introduce a Mathematica code, StableWein, that implements this idea. The user is allowed to choose the level of accuracy that they want in the determination of BnessFB; more precision means the use of more necessary conditions, and usually entails a longer running time for the code. Our investigation suggests that our procedure and code can be extremely precise in the determination of the potentials that are BFB. In addition, we introduce a machine-learning code that identifies, with more than 99% accuracy, which potentials are BFB.

    hep-phSciPost Phys.Core(2026)·1 citation
23. 23*

    Radiative corrections to two-neutrino double-beta decay

    Jordy de Vries🇳🇱 · Emanuele Mereghetti🇺🇸 · Saad el Morabit🇳🇱 · Stefan Sandner🇺🇸

    We use heavy-nucleus effective field theory to compute radiative corrections to two-neutrino double-$\beta$ decay ($2\nu \beta \beta$). Our main result is the first derivation of a universal radiative-correction factor for double-weak decays -- the analogue of the Sirlin function in single-$\beta$ decay -- independent of nuclear matrix elements and excitation energies. This "double-weak Sirlin function" depends on the individual electron energies as well as their relative angle and differs significantly from the approximation obtained by summing two single-$\beta$ decay Sirlin functions. In addition, we calculate the nuclear-structure-dependent component of the radiative corrections and find that they can still be neglected at current experimental sensitivities. On the other hand, the double-weak Sirlin function induces distortions of the electron energies and angular spectra that are comparable in size to the leading nuclear-structure corrections parametrized by the ratio of nuclear matrix elements, ${\xi }_{31}$. Our results indicate that extractions of nuclear structure information and tests of the Standard Model from high-precision $2\nu \beta \beta$ measurements must include double-weak radiative corrections, implying that recent extractions of ${\xi }_{31}$ should be revisited.

    hep-phnucl-exnucl-thPRL(2026)·0 citations
24. 24*

    A Breath of Fresh Air for Molière: Detecting Molière Scattering using Jet Substructure Observables in Oxygen Collisions

    Arjun Srinivasan Kudinoor🇺🇸 · Arthur Yi-Ting Lin🇺🇸 · Daniel Pablos🇪🇸 · Krishna Rajagopal🇺🇸

    Ultra-relativistic oxygen-oxygen (OO) collisions are a promising arena in which to probe rare, large-angle, high momentum-transfer $2\to 2$ Molière scatterings between energetic jet partons and quasiparticles in quark-gluon plasma (QGP). As a jet propagates through the droplet of QGP formed in the same collision, its constituents lose energy to and excite wakes in the medium, and may scatter off quark- and gluon-like quasiparticles in QGP. Using the hybrid strong/weak coupling model, we show that including Molière scatterings between jet partons and medium quasiparticles is essential to reproduce recent CMS measurements of charged-particle suppression in OO collisions with this model. We then present the first theoretical study of how jet-medium interactions modify the internal structure of jets in OO collisions. We find that Molière scatterings broaden the Soft Drop splitting angle $R_g$, enhancing the population of $R=0.4$ and $R=0.8$ jets with $R_g\gtrsim 0.2$ in OO collisions relative to pp collisions. Energy-energy correlators (EECs) provide a complementary probe, exhibiting enhanced large-angle correlations within jets due to jet-induced wakes and Molière scattering. In both cases, we propose an experimental measurement where the relevant OO/pp ratio can, if enhanced above unity in future data as in our calculations, be a distinctive, model-independent, detection of hard scattering off QGP quasiparticles. We furthermore use our calculations of EECs to show how the angular scale corresponding to the deflection of jet or medium partons by Molière scattering is imprinted in the EEC for jets with radius $R_{\mathrm{jet}}\sim 0.8$ in OO collisions. These results demonstrate that jet substructure measurements in OO collisions are promising avenues to probe the quasiparticles that emerge at short distances within an otherwise strongly coupled medium.

    hep-phhep-thnucl-exnucl-th5 citations
25. 25*

    Enhanced Dark Matter Quantum Sensing via Geometric Phase

    Xiaolin Ma🇯🇵 · Jie Sheng🇯🇵

    We propose a quantum sensing protocol for coupled qubit-oscillator systems that surpasses the standard quantum limit by exploiting a geometric phase for dark matter searches. Instead of letting the cavity evolve freely under a weak dark matter background, we combine large coherent displacements and squeezing operations within the evolution protocol, thereby mapping the signal onto an enhanced geometric phase. This new protocol increases the quantum Fisher information to surpass standard quantum limit and leads to a substantial improvement in dark photon and axion detection sensitivity, opening a new paradigm for cavity-based dark matter detection.

    hep-phquant-ph3 citations
26. 26*

    Kummitus: a light-weight toolbox for counting DOF in perturbative QFT

    Carlo Marzo🇪🇪

    The consistent construction of quantum field theories beyond the simplest cases requires a precise characterization of the propagating degrees of freedom. These are encoded in the single-pole structure of two-point functions, a connection firmly established through foundational theoretical work of the last century. While high-level programs for spectral analysis are publicly available, we felt the need to complement the existing landscape with a tool that reaches the gauge-invariant propagator by the shortest possible algorithmic path. This is the purpose of \texttt{Kummitus}, an open-source Wolfram Mathematica toolbox designed to do precisely that: compute the (gauge-invariant) propagator. Beyond its utility in research applications, \texttt{Kummitus} is intended as an accessible and transparent resource for the theoretical community, with particular value for pedagogical purposes.

    ↳ hep-thhep-ph1 citation
27. 27*

    Automated Extraction of Collins-Soper Kernel from Lattice QCD using An Autonomous AI Physicist System

    Jin-Xin Tan🇨🇳 · Ting-Jia Miao🇨🇳 · Mu-Hua Zhang🇨🇳 · Xiang-He Pang🇨🇳 · Ze-Xi Liu🇨🇳 · Lin-Feng Zhang🇨🇳 · Si-Heng Chen🇨🇳 · Wei Wang🇨🇳

    We employ {PhysMaster}, an autonomous agentic AI system integrating theoretical reasoning, numerical computation, and exploitation strategies towards ultra-long horizon automation, to tackle long-standing challenges in non-perturbative lattice analyzes, including low signal-to-noise ratio at large transverse separation, complex systematic uncertainties, and labor-intensive manual workflows. Using the extraction of the CS kernel from quasi-transverse-momentum-dependent wave functions (quasi-TMDWFs) via large-momentum effective theory (LaMET) as a showcase, we demonstrate that \textsc{PhysMaster} automates high-dimensional fitting, renormalization, continuum-chiral extrapolation, and non-perturbative reconstruction in a fully autonomous manner. This framework drastically reduces the duration of the workflow from months to hours without compromising precision, stabilizes signals in the large-$b_{\perp }$ region to $1\mathrm{fm}$, and produces results consistent with perturbative QCD and state-of-the-art traditional lattice calculations. This work validates the effectiveness of physicist-AI collaboration for first-principles QCD research and establishes a generalizable, reproducible paradigm for automated studies of parton structure and other non-perturbative observables from lattice QCD.

    ↳ hep-lathep-ph5 citations
28. 28*

    Structure of QC${}_2$D ground state fields at nonzero matter densities

    Ragib F. Hasan🇦🇺 · Matthew Cummins🇦🇺 · Waseem Kamleh🇦🇺 · Dale Lawlor🇮🇪 · Derek Leinweber🇦🇺 · Ian van Schalkwyk🇦🇺 · Jon-Ivar Skullerud🇮🇪

    A quantitative investigation into the modification of ground-state field structures in two-color QCD (QC${}_2$D) is presented at finite chemical potential. Using lattice simulations with Wilson gauge and fermion actions, we explore the chromo-electromagnetic field strengths under varying matter densities. To ensure accurate measurements, we develop and calibrate two highly improved topological charge operators and evaluate four gradient flow actions. Our results reveal a finite-volume crossover in the regime of the anticipated phase boundary at $\mu =m_{\pi }/2$, with both chromo-electric and chromo-magnetic field strengths suppressed before recovering and exceeding vacuum values at higher chemical potentials. We find the difference between the squared chromo-electric and chromo-magnetic field strengths, $E^2-B^2$, to increase in magnitude monotonically with increasing chemical potential. At $a\mu =0.7$, we find an $11\%$ suppression of $E^2$, a relatively small effect. A systematic analysis using sigmoid fits of lattice simulations in the crossover regime is performed to confirm the critical chemical potential obtained from the field structure is in agreement with the phase boundary at $m_{\pi }/2$. These findings provide new insight into non-Abelian ground-state vacuum field structures and offer a foundation for future studies in real QCD.

    ↳ hep-lathep-phnucl-th1 citation
29. 29*

    Astrophysical aspects of string compactifications

    Mario Ramos-Hamud🇬🇧

    A generic aspect of low-energy effective field theories (EFTs) coming from string compactifications is the appearance of moduli fields. Among these moduli, the axion and dilaton are present as (pseudo-) Goldstone bosons from the spontaneous breaking of an exact (or approximate) global symmetry. These moduli have a different microscopic coupling to matter but appear kinetically coupled in such a way that their interaction can compete with gravity at low energies and have an important effect in strong gravity environments. In this talk, we will discuss some of the astrophysical implications of a stringy-inspired multi-scalar-tensor theory. In particular, we show the numerical solution of the Tolman-Oppenheimer-Volkov (TOV) system of equations, necessary to probe the existence of a screening mechanism that reduces the Brans-Dicke dilaton coupling to macroscopic matter sources such as a neutron star.

    ↳ hep-thastro-ph.HEhep-phPoS(2026)·0 citations
30. 30*

    Hall Viscosity in the Quark-Gluon Plasma

    Sukrut Mondkar🇮🇳 · Giorgio Torrieri🇧🇷 · Matthias Kaminski🇺🇸 · René Meyer🇩🇪

    We study the Hall viscosity of the quark gluon plasma (QGP) created in non-central heavy-ion collisions. In the presence of a strong magnetic field or vorticity, rotational symmetry is broken from O(3) to O(2), allowing for two independent Hall viscosities associated with shear deformations transverse and parallel to the symmetry-breaking direction. We find the corresponding constitutive relations by extending the kinetic-theory mechanism to three spatial dimensions and provide parametric estimates of the Hall viscosities under realistic QGP conditions. Both kinetic-theory and holographic estimates indicate that Hall viscosities are comparable in magnitude to the shear viscosity at zero magnetic field. We further show that Hall viscous stresses at hydrodynamic initialization can be as large as standard viscous corrections and identify observable consequences in flow and event-plane correlations.

    ↳ nucl-thhep-phhep-th0 citations
31. 31*

    Derivation of the Kompaneets equation using the boost operator approach

    Alex Hoey🇬🇧 · Jacob Long🇬🇧 · Jens Chluba🇬🇧

    The repeated scattering of photons by thermal electrons at low temperatures is described by the Kompaneets equation and its generalized forms that include anisotropies and higher order temperature corrections. In this work, we use the boost operator approach to derive the related expressions in a transparent way that showcases the generality of the formalism and its application to radiative transfer problems. We consider the simplest form of the Kompaneets equation for the scattering in isotropic media at the leading order in the electron temperature and then include anisotropies in the photon field, reproducing previously obtained expressions for the evolution equations. For this we use expressions for the scattering operator in the electron rest frame up to first order in the electron recoil, O(h nu/m_e c^2), but then work at all orders in the electron momentum, p, as easily obtained with the boost operator approach. This shows how specific transformation rules can be formulated that allow simplification of the otherwise cumbersome and repetitive calculations. We also confirm the expressions for higher order temperature corrections in isotropic media, highlighting the validity of the approach presented here. As part of the derivation, we find expressions for the boost operator in general boost directions which we believe will also be useful in other applications of the formalism.

    ↳ astro-ph.COhep-phJCAP(2026)·1 citation
32. 32*

    Searching for Anomalies with Foundation Models

    Vinicius Mikuni🇯🇵 · Benjamin Nachman🇺🇸

    Foundation models have the potential to extend the discovery reach for anomaly detection searches. When studying the large OmniLearned foundation model on data from the CMS experiment, unexpected behavior was observed in a mass sideband. The purpose of this paper is to perform a full analysis, including a complete background estimate, on the phase space picked out by the large model. We find that the background estimation describes the data well in validation regions, but is unable to accurately model the signal region. We invite further scrutiny of these events and our methods.

    ↳ hep-exhep-phphysics.data-an2 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.