Mon·Jul 21, 2025Monday·July 21, 2025

1. 01*

   Quark + Diquark Description of Nucleon Elastic Electromagnetic Form Factors

   Peng Cheng🇨🇳 · Zhao Qian Yao🇪🇸 · Daniele Binosi🇮🇹 · Ya Lu🇨🇳 · Craig D. Roberts🇨🇳

   Working with a Poincaré-covariant quark + diquark, $q(qq)$, Faddeev equation approach to nucleon structure, a refined symmetry preserving current for electron + nucleon elastic scattering is developed. The parameters in the interaction current are chosen to ensure that the $q(qq)$ picture reproduces selected results from contemporary $3$-body analyses of nucleon elastic electromagnetic form factors. Although the subset of fitted results is small, the $q(qq)$ picture reproduces almost all the $3$-body predictions and often results in better agreement with available data. Notably, the $q(qq)$ framework predicts a zero in $G_E^p/G_M^p$, the absence of such a zero in $G_E^n/G_M^n$, and a zero in the proton's $d$-quark Dirac form factor. Derived $q(qq)$ results for proton flavour-separated light-front-transverse number and anomalous magnetisation densities are also discussed. With the $q(qq)$ framework thus newly benchmarked, one may proceed to comparisons with a broader array of $3$-body results. This may enable new steps to be made toward answering an important question, viz. is the quark + fully-interacting diquark picture of baryon structure only a useful phenomenology or does it come close to expressing robust features of baryon structure?

   hep-phhep-exhep-latnucl-ex+1EPJA(2025)·8 citations
2. 02*

   ${\pi }^0\to 2\gamma$ decay under strong magnetic fields in the NJL model

   Máximo Coppola🇦🇷 · Daniel Gomez Dumm🇦🇷 · Norberto N. Scoccola🇦🇷

   We study the anomalous ${\pi }^0\to \gamma \gamma$ decay under an external uniform magnetic field in the framework of a two-flavor Nambu-Jona-Lasinio model. It is seen that the full decay width gets strongly reduced with the external field, and that the differential width is almost independent of the direction of the outgoing photons. We also find that the result for the total width can be very well approximated by a simple expression obtained at the lowest order in the chiral expansion, which is just a direct extension to finite magnetic fields of the well-known $B=0$ result that follows from the anomalous Wess-Zumino-Witten action. As a result, the magnetic suppression of the width can be understood in terms of the evolution of both the neutral pion mass and decay constant with the magnetic field.

   hep-phhep-latPRD(2025)·6 citations
3. 03*

   Range of topological fluctuations in the three-flavor linear sigma model

   G. Fejos🇭🇺 · A. Patkos🇭🇺

   The topological charge density two-point function is computed in a three-flavor effective linear meson model, including contributions from topological sectors with arbitrary charge. A corresponding composite field is introduced via a Hubbard-Stratonovich transformation. In the $\eta$-$\eta$' sector, the model yields very accurate spectroscopy with negligible mixing with the composite field. The resulting topological susceptibility allows for the extraction of a surprisingly large absolute scale for the range of topological fluctuations. When compared with various QCD-based estimates, this indirectly suggests the dominance of higher topologically charged configurations in the ground state.

   hep-phPRD(2025)·2 citations
4. 04*

   Gluon Wigner distributions with transverse polarization at non-zero skewness

   Sujit Jana🇮🇳 · Kenil Solanki🇮🇳 · Vikash Kumar Ojha🇮🇳

   We investigate the gluon Wigner distributions at non-zero skewness using light-front wave functions (LFWFs) in the dressed quark model, where the target state is a quark dressed with a gluon in the leading-order Fock space expansion. Our analysis focuses on the configurations in which the gluon, the target, or both are transversely polarized. We derive analytical expressions for the Wigner distributions in the boost-invariant longitudinal space ($\sigma$) for transversely polarized configurations and observe a diffraction-like oscillatory pattern in $\sigma$-space, analogous to that reported earlier for unpolarized and longitudinally polarized gluons.

   hep-phCPC(2026)·0 citations
5. 05*

   The equation of state and surface tension of QCD in the first order phase transition region

   Yuan-jun Mei🇨🇳 · Yi Lu🇨🇳 · Fei Gao🇨🇳 · Yu-xin Liu🇨🇳

   We build up a complete description of QCD phase structure by applying the parametrization of the chiral and deconfinement order parameters upon the calculations from functional QCD approaches. In particular in the first order phase transition region at high chemical potential, both the phase transition line using Maxwell construction and the coexistence boundary lines from the spinodal decompostion are determined. We compute the thermodynamic quantities including the number density, the energy density, the pressure and also the free energy for both stable and unstable phases of QCD. Additionally, after applying a phenomenological description of the inhomogeneity of the QCD free energy, we obtain the surface tension of the first order phase transition of QCD.

   hep-phhep-thnucl-exnucl-thPRD(2026)·3 citations
6. 06*

   Triply heavy tetraquarks $\bar{b}c\bar{q}c$ and $\bar{c}b\bar{q}b$ in a constituent quark model

   Gang Yang🇨🇳 · Jialun Ping🇨🇳 · Jorge Segovia🇪🇸

   A systematic investigation of $S$-wave triply heavy tetraquark systems with quark content $\bar{b}c\bar{q}c$ and $\bar{c}b\bar{q}b$ $(q=u,d,s)$, spin-parity quantum numbers $J^P=0^{+}$, $1^{+}$, $2^{+}$ and isospin $I=0,\frac{1}{2}$, is carried out within the constituent quark model framework. The four-body bound and resonance states are determined by solving the Schrödinger equation employing the high-precision and efficient Gaussian Expansion Method (GEM) in conjunction with the powerful Complex Scaling Method (CSM). Besides, a comprehensive coupled-channel analysis of the $S$-wave tetraquark systems is performed, taking into account meson-meson, diquark-antidiquark and K-type configurations, as well as all allowed color structures. Several narrow resonant states are identified in each $I(J^P)$ channel. In particular, resonances for the $\bar{b}c\bar{q}c$ system are found in the mass range of $8.87-9.36$ GeV, while those for the $\bar{c}b\bar{q}b$ system lie between $12.13-12.45$ GeV. Most of the predicted resonances are compact tetraquark states with sizes smaller than $1.0$ fm, although four states exhibit more extended structures with sizes around $1.3$ fm, suggesting a more loosely bound nature. Magnetic moments and dominant wave function components of these exotic states are also analyzed. The results indicate that K-type configurations play a major role in the structure of the observed resonances. Finally, possible strong decay channels (golden modes) for these states are theoretically proposed.

   hep-phhep-exhep-latnucl-ex+1PRD(2026)·4 citations
7. 07*

   Form factors and phenomenology of ${\mathbf{B}}_{(\mathbf{s})}$ and ${\mathbf{D}}_{(\mathbf{s})}$ semileptonic decays to $\mathbf{\eta }$ and ${\mathbf{\eta }}^{\prime }$

   Blaženka Melić🇭🇷 · Méril Reboud🇫🇷

   Motivated by more precise recent measurements of the $B\to \eta \ell \nu$ and $D_{(s)}\to {\eta }^{(\prime )}\ell \nu$ decays, we employ state-of-the-art parametrizations to describe the $B_{(s)},D_{(s)}\to {\eta }^{(\prime )}$ form factors across the full $q^2$ range, fitting them to the latest light-cone sum rule results. Using these results, we compute the branching ratios for all relevant decays and compare them with experimental data, finding good agreement. Additionally, we examine the validity and precision of the extracted $\eta$-${\eta }^{\prime }$ mixing angle in the context of heavy meson decays. By combining our predictions for the $B,D,D_s\to {\eta }^{(\prime )}$ form factors with recent semileptonic decay measurements, we extract the CKM elements $|V_{ub}|$, $V_{cs}$, and $V_{cd}$. We also provide tests of the lepton flavour universality in the $B,D,D_s\to {\eta }^{(\prime )}\ell \nu$ decays and present results for the forward-backwards asymmetries in these decays. Our findings indicate that the extracted values are becoming comparable in precision to those obtained from more conventional semileptonic decay analyses.

   hep-phJHEP(2025)·3 citations
8. 08*

   Revisiting the ${\Lambda }_c^{+}\to \Lambda \eta {\pi }^{+}$ and the roles of intermediate resonances

   En Wang🇨🇳 · Wen-Tao Lyu🇨🇳 · Man-Yu Duan🇨🇳 · Chu-Wen Xiao🇨🇳 · Dian-Yong Chen🇨🇳 · Ju-Jun Xie🇨🇳 · Eulogio Oset🇪🇸

   In this paper, we first review the theoretical and experimental studies of the process ${\Lambda }_c^{+}\to {\pi }^{+}\eta \Lambda$. Motivated by the recent BESIII and Belle measurements, we have conducted a theoretical study of the process ${\Lambda }_c^{+}\to {\pi }^{+}\eta \Lambda$, where the $a_0(980)$ and $\Lambda (1670)$ resonances are dynamically generated from the $S$-wave meson meson and meson baryon interaction, respectively. Our results give a reasonable description of the invariant mass distributions, which implies that the spin flip contribution in the $\Sigma (1385)$ excitation plays an important role.

   hep-phPoS(2026)·0 citations
9. 09*

   Charged lepton flavor violating decays with a pair of light dark matter and muonium invisible decay

   Sahabub Jahedi🇨🇳 · Yi Liao🇨🇳 · Xiao-Dong Ma🇨🇳

   In this paper, we initiate the study of lepton flavor violating (LFV) dark matter (DM) interactions, expanding our focus beyond the flavor-conserving DM interactions typically considered in conventional direct and indirect detections. We work in an effective field theory (EFT) framework, focusing on the leading-order local operators of the form, ${\bar{\ell }}_j\Gamma {\ell }_i{\mathtt{DM}}^2$, where $(ij)=(e\mu ,e\tau ,\mu \tau )$ and the DM includes the three well-known scenarios: a scalar, a fermion, and a vector. We derive the invariant-mass distribution for the three-body decay ${\ell }_i\to {\ell }_j+\mathtt{DM}+\mathtt{DM}$ and demonstrate that it can be used to distinguish between different operator structures and to determine the DM mass. By utilizing current experimental bounds on the charged muon LFV decay involving neutrinos and the ratio of tau leptonic decay widths, we establish stringent limits on the effective scale associated with each operator. Additionally, for the $e\mu$ flavor combination, we investigate the muon four-body radiative decay ($\mu \to e+\mathtt{DM}+\mathtt{DM}+\gamma$) to complement our probe of such interactions. Finally, we examine muonium invisible decays based on the derived bounds on the effective operators and find that the branching ratios can be significantly enhanced compared to the predictions of the standard model. In particular, any future observation of the para-muonium invisible decay serves as a compelling signature for these flavored DM interactions.

   hep-phJHEP(2026)·6 citations
10. 10*

    ${\rm Y}(5S)$ in the unquenched quark model

    Xiaoyun Chen🇨🇳 · Yue Tan🇨🇳 · Yuan Chen🇨🇳 · Xuejie Liu🇨🇳 · Jialun Ping🇨🇳

    The observation of the ${\rm Y}(10753)$ state by Belle II Collaboration has sparked significant interest in the theoretical understanding of such states within the context of hadron physics. Considering the similar mass and the decay with, as well as the same quantum numbers $J^{PC}=1^{--}$ with the ${\rm Y}(10860)$ state, which is referred to be the ${\rm Y}(5S)$ in PDG, in this work, we try to calculate the mass of the ${\rm Y}(5S)$ state. The model used to predict the high-energy spectrum of these states generally involves a constituent quark model, which can describe a variety of properties of hadrons containing heavy quarks. In the framework of the unquenched quark model, a coupled-channel calculation is employed to explore the effect of open-bottom meson-meson thresholds on the ${\rm Y}(10860)$ state. The hypothesis is that coupled-channel effects could be large enough to create new dynamically generated states, thus potentially explaining the nature of the ${\rm Y}(10860)$ state, as well as whether the ${\rm Y}(10860)$ and ${\rm Y}(10753)$ is the same state. The results indicate that unquenched effects play a crucial role in explaining the ${\rm Y}(10860)$ state, providing a plausible mechanism for its formation. Besides in our calculations, the ${\rm Y}(10860)$ and ${\rm Y}(10753)$ may be two different states.

    hep-phMod.Phys.Lett.A(2026)·1 citation
11. 11*

    Freeze-in gravitational waves and dark matter in warm inflation

    Quan Chen🇨🇳 · Siyu Jiang🇨🇳 · Dayun Qiu🇨🇳 · Peilin Chen🇨🇳 · Fa Peng Huang🇨🇳

    Recent study [1] has suggested that warm inflation may be realized with a minimal extension of the Standard Model by a single scalar inflaton field with an axion-like coupling to gluons. Motivated by this framework, we investigate the gravitational wave spectrum and graviton-portal dark matter production through the freeze-in process generated during warm inflation scenarios. We perform a comparative analysis for different dissipation terms, focusing on their distinct gravitational wave signatures in the high-frequency regime. Our findings reveal qualitative and quantitative differences in the spectral behavior, offering a preliminary pathway for exploring inflationary and dark matter models through high-frequency gravitational wave signals.

    hep-phastro-ph.COJCAP(2026)·4 citations
12. 12*

    Probing dark-state electromagnetic form factors at future linear electron-positron colliders with polarized beams

    Zhong Zhang🇨🇳 · Yu Zhang🇨🇳 · Zeren Simon Wang🇨🇳 · Yunlan Ji🇨🇳

    We study the electromagnetic form factors of electrically neutral dark-sector particles in this paper. Concretely speaking, we focus on operators that can lead to interactions of fermionic dark states with the Standard-Model (SM) photon, including both dimension-5 (the magnetic and electric dipole moments) and dimension-6 (the anapole moment and charge radius) operators. Correspondingly, instead of the SM-photon form factors, we employ hypercharge gauge-field form factors that can induce additional couplings to the SM $Z$-boson. Utilizing the mono-photon production channel at future linear electron-positron colliders, the International Linear Collider (ILC) and the Compact Linear Collider (CLIC), we demonstrate that tuning beam polarization allows for simultaneous enhancement of signal-event rates and suppression of dominant SM background events, i.e.~neutrino-induced processes, and hence improvement of sensitivity reach. Our analysis reveals that ILC and CLIC can probe electromagnetic form factors of dark-sector particles up to about two orders of magnitude beyond existing experimental limits. We also estimate, at the order-of-magnitude level, the validity range of the effective-field-theory (EFT) approach we adopt, finding that for the dimension-5 operators the EFT remains valid in most of the parameter regions to which the ILC and CLIC can be sensitive, while it breaks down in the entire sensitivity region for the dimension-6 operators.

    hep-phhep-exJHEP(2025)·0 citations
13. 13*

    Neutron emission associated with $\gamma \gamma \to \gamma \gamma$ scattering in UPC of heavy ions at the LHC

    Pawel Jucha🇵🇱 · Mariola Klusek-Gawenda🇵🇱 · Antoni Szczurek🇵🇱

    We calculate cross sections for the production of different neutron classes $0n0n$, $0nXn+Xn0n$ and $XnXn$, possible to measure in Zero Degree Calorimeters (ZDCs), associated with photon-photon scattering in UPC of lead on lead. The calculations are performed for the ATLAS kinematics. Our calculations for neutron classes are tested against existing data for ${\rho }^0$ production in UPC. We get a good agreement for absolute cross section as well as very good results for fractional cross section which gives confidence to the analogous calculation for diphoton production, corresponding to $\gamma \gamma \to \gamma \gamma$ scattering. We present both absolute as well as fractional cross sections for the different neutron classes. We also show different distributions in impact parameter, photon rapidity, transverse momentum, diphoton invariant mass and photon rapidity difference. The shapes of the photon distributions depend on the neutron classes which we quantify in this paper. It would be valuable to test our predictions using the ATLAS main detector and the ATLAS ZDCs.

    hep-phnucl-thPRD(2025)·4 citations
14. 14*

    Anomalous-magnetic-moment-enhanced Casimir effect

    Daisuke Fujii🇯🇵 · Katsumasa Nakayama🇯🇵 · Kei Suzuki🇯🇵

    We theoretically investigate the impact of the anomalous magnetic moment (AMM) of Dirac fermions on the fermionic Casimir effect under magnetic fields. We formulate it as an extension of the well-known Lifshitz formula. From our formula, we find that the AMM increases the fermionic Casimir energy. In particular, when the AMM is large enough, the Casimir energy is significantly enhanced by the gapless behavior of the lowest Landau level. We also quantitatively estimate the Casimir energy from electron, muon, and constituent quark fields under magnetic fields and propose possible phenomena at finite temperature and fermion density.

    hep-phhep-thnucl-thquant-phPRD(2026)·1 citation
15. 15*

    Deep Image Reconstruction for Background Subtraction in Heavy-Ion Collisions

    Umar Sohail Qureshi🇺🇸 · Raghav Kunnawalkam Elayavalli🇺🇸

    Jet reconstruction in an ultra-relativistic heavy-ion collision suffers from a notoriously large, fluctuating thermal background. Traditional background subtraction methods struggle to remove this soft background while preserving the jet's hard substructure. In this Letter, we present DeepSub, the first machine learning-based approach for full-event background subtraction. DeepSub utilizes a model based on Swin Transformer layers to denoise jet images and disentangle hard jets from the heavy-ion background. DeepSub significantly outperforms existing subtraction techniques by reproducing key jet observables such as jet $p_{\mathrm{T}}$ and mass, and substructure observables such as girth and the energy correlation function, at the sub-percent to percent level. As such, DeepSub paves the way for precision heavy-ion measurements in hitherto inaccessible kinematic regimes.

    hep-phnucl-exnucl-thphysics.data-anPRC(2025)·4 citations
16. 16*

    Global Bayesian Analysis of $\mathrm{J}/\psi$ Photoproduction on Proton and Lead Targets

    Heikki Mäntysaari🇫🇮 · Hendrik Roch🇺🇸 · Farid Salazar🇺🇸 · Björn Schenke🇺🇸 · Chun Shen🇺🇸 · Wenbin Zhao🇺🇸

    We perform a global Bayesian analysis of diffractive $\mathrm{J}/\psi$ production in $\gamma +p$ and $\gamma +\mathrm{Pb}$ collisions using a color glass condensate (CGC) based calculation framework. As past calculations have shown that CGC-based models typically overpredict the $\mathrm{J}/\psi$ production in $\gamma +\mathrm{Pb}$ collisions at high center of mass energy, we address the question of whether it is possible to describe coherent and incoherent diffractive $\mathrm{J}/\psi$ data from $\gamma +p$ collisions at HERA and the LHC, and from $\gamma +\mathrm{Pb}$ collisions at the LHC simultaneously. Our results indicate that a simultaneous description of $\gamma +p$ and $\gamma +\mathrm{Pb}$ data is challenging, with results improving when an overall $K$-factor -- scaling $\gamma +p$ and $\gamma +\mathrm{Pb}$ cross sections to absorb model uncertainties -- is introduced.

    hep-phnucl-thPRD(2026)·21 citations
17. 17*

    Symmetrizing relativistic three-body partial wave amplitudes

    Andrew W. Jackura🇺🇸 · Nicholas C. Chambers🇺🇸 · Raúl A. Briceño🇺🇸

    S matrix principles and symmetries impose constraints on three-particle scattering amplitudes, which can be formulated as a class of integral equations for their partial wave projections. However, these amplitudes are typically expressed in an asymmetric basis, where one of the initial and final state particles is singled out, and all quantum numbers are defined relative to this spectator. In this work, we show how to construct symmetric partial wave amplitudes, which have been symmetrized over all possible spectator combinations, using their asymmetric counterparts and sets of recoupling coefficients. We derive these recoupling coefficients for arbitrary angular momentum and isospin for arbitrary systems of spinless particles with SU(2) flavor symmetry. We propose a simple intensity observable suitable for visualizing the structure of three-body dynamics in Dalitz distributions. Finally, we provide some numerical examples of Dalitz distributions relevant for future lattice QCD calculations of $3\pi$ systems and provide numerical evidence that the symmetrization procedure is consistent with expected symmetries of Dalitz plots.

    hep-phhep-lathep-thnucl-thPRD(2026)·5 citations
18. 18*

    A quantum algorithm for the n-gluon MHV scattering amplitude

    Erik Bashore🇸🇪 · Stefano Moretti🇬🇧 · Timea Vitos🇸🇪

    We propose a quantum algorithm for computing the n-gluon maximally helicity violating (MHV) tree-level scattering amplitude. We revisit a newly proposed method for unitarisation of non-unitary operations and present how this implementation can be used to create quantum gates responsible for the color and kinematic factors of the gluon scattering amplitude. As a proof-of-concept, we detail the full conceptual algorithm that yields the squared amplitude and implement the corresponding building blocks on simulated noiseless quantum circuits for n = 4 to analyze its performance. The algorithm is found to perform well with parameter optimizations, suggesting it to be a good candidate for implementing on quantum computers also for higher multiplicities.

    hep-phhep-thquant-phSciPost Phys.(2026)·4 citations
19. 19*

    The Rise of Particle Physics

    S. Ting · H. Georgi · J. Iliopoulos · L. Maiani · A. De Rujula · L. Di Lella · S. Myers · F. Marion · M. Pierini · G. Martinelli · R. Barbieri · G. Battimelli and 3 other authors

    Discovery of the J Particle at Brookhaven National Laboratory and the Physics of Electrons and Positrons; The Standard Model Yesterday, Today and Tomorrow; The Rise of Gauge Theories: From Many Models to One Theory; From Charm to CP Violation; When the Standard Model Was Ignored; The Discovery of the W and Z Bosons at the CERN Proton-Antiproton Collider; A Personal History of CERN Particle Colliders (1972-2022); The Age of Gravitational Wave Astronomy; Precision Physics in the Era of (HL)LHC; Recent Developments in Flavor Physics, the Unitary Triangle Fit, Anomalies and All That; About BSM Physics, with Emphasis on Flavour; The Discovery of the Antiproton between Rome and Berkeley; Raoul Gatto and Bruno Touschek: the Rise of $e+e^{-}$ Physics; From ADONE's Multi-Hadron Production to the J/$\Psi$ Discovery; From Bjorken Scaling to Scaling Violations

    hep-phHiHEP(2025)·0 citations
20. 20*

    Spectral Surgery in a Heat Bath: a finite-temperature guide to particle production for phenomenologists

    Nirmalya Brahma🇨🇦 · Saniya Heeba🇨🇦 · Hugo Schérer🇨🇦 · Katelin Schutz🇨🇦

    Quantifying the effects of finite temperature and density (FTD) on particle properties is essential for understanding phenomena within and beyond the Standard Model. In this work, we present a simplified framework for calculating particle production rates at FTD without resorting to a full thermal field theory calculation. We do so by relating the imaginary part of a particle's $n$-loop finite temperature self energy, which defines its in-medium damping rate, to a sum of thermally weighted tree-level vacuum rates. Such a mapping results in novel "interference" contributions to particle production which have no vacuum analog and which have been relatively overlooked in the phenomenology literature. These interference terms are known to regulate collinear and infrared divergences that arise when calculating interaction rates in a medium. We demonstrate the impact of these corrections with two toy models and find that properly accounting for these interference terms can alter particle production by an $O(1)$ amount. We additionally compare the size of these corrections to the thermal mass corrections often studied in the literature, finding the sizes of these contributions to be of similar order.

    hep-phphysics.plasm-phJHEP(2026)·3 citations
21. 21*

    Universal parameters of the $\Lambda (1380)$, the $\Lambda (1405)$ and their isospin partners from a combined analysis of Lattice QCD and experimental results

    Ferenc Pittler🇨🇾 · Maxim Mai🇺🇸 · Ulf-G. Meißner🇩🇪 · Ryan F. Ferguson🇬🇧 · Peter Hurck🇬🇧 · David G. Ireland🇬🇧 · Bryan McKinnon🇬🇧

    We perform a global analysis of lattice and experimental data on negative-strangeness meson-baryon scattering using a large set of variations of the theoretical framework based on the Chiral Unitary Approach. For the former, the Lüscher formalism is utilized taking into account all pertinent coupled-channel effects. Through this, systematic uncertainties related to data scarcity, potential ambiguities, and possible framework dependence are quantified for the first time. The implementation of information criteria and other statistical tools is discussed. As a final result we provide pole positions for isoscalar resonances at the physical and lattice points including statistical and systematic uncertainties. Predictions for the isovector states are also provided showing large uncertainties.

    hep-phhep-latnucl-thPRD(2025)·11 citations
22. 22*

    Dark matter pair absorption

    Martin Bauer🇬🇧 · Javier Perez-Soler🇪🇸 · Jack D. Shergold🇪🇸

    We present a comprehensive analysis of the sensitivity of atomic transitions to light dark matter pair absorption. Unlike scattering, where only a fraction of the dark matter energy is deposited, pair absorption processes absorb the full mass, and are therefore capable of constraining far lighter dark matter. Spin-flip and fine structure transitions are able to constrain electroweak scale axial-vector couplings for bosonic dark matter with $\mu \mathrm{eV}$ to eV masses, whilst principal quantum number transitions are able to set similar constraints on bosonic dark matter with scalar couplings. Unfortunately, pair absorption is largely insensitive to light fermionic DM due its necessarily tiny density at low masses. We also demonstrate the sensitivity of pair absorption to the cosmic neutrino background, and find that spin-flip transitions can set constraints on the overdensity parameter of ${\eta }_{\nu }\lesssim 10^9$ for neutrino masses $m_{\nu }\lesssim 1\mathrm{meV}$, around a hundred times stronger than existing constraints.

    hep-phPRD(2026)·2 citations
23. 23*

    The electroweak precision constraints of the 2HDM+S

    Cheng Li🇨🇳 · Juxiang Li🇨🇳 · Shufang Su🇺🇸 · Wei Su🇨🇳

    The 2HDM+S is the singlet extension of the Two-Higgs-Doublets Model (2HDM). The singlet field and its mixing with the 2HDM Higgs sector lead to new contributions to the electroweak precision observables, in particular, the oblique parameters. In this paper, we identify five benchmark cases, where at most one mixing angle is nonzero and analyze the 95% C.L. allowed parameter space by the oblique parameters. In the alignment limit of the 2HDM, we find that other than the usual mass relations of $m_H\sim m_{H^{\pm }}$ or $m_A\sim m_{H^{\pm }}$, electroweak precision measurements also impose an upper limit on the neutral Higgs masses. In the cases with nonzero singlet mixing with the 2HDM Higgses $H$ or $A$, we find approximate mass relations of $c_{{\alpha }_{HS}}^2{m}_H+s_{{\alpha }_{HS}}^2{m}_{h_S}=m_{H^{\pm }}$ or $c_{{\alpha }_{AS}}^2{m}_A+s_{{\alpha }_{AS}}^2{m}_{A_S}=m_{H^{\pm }}$. Those relations are universal to the 2HDM+S models, with or without further symmetry assumption. We also study the non-alignment limit of the 2HDM+S, which typically has tighter constraints on the masses and mixing angles. At the end, we examine the complementarity between the electroweak precision analyses and the Higgs coupling precision measurements.

    hep-phCPC(2026)·5 citations
24. 24*

    Functional inference on deviations from General Relativity

    Costantino Pacilio🇮🇹 · Riccardo Buscicchio🇮🇹

    Extensions of general relativity often predict modifications to gravitational waveform morphology that depend functionally on source parameters, such as the masses and spins of coalescing black holes. However, current analyses of strong-field gravity lack robust, data-driven methods to infer such functional dependencies. In this work, we introduce GRANITA, a non-perturbative, theory-agnostic framework to characterize parameter-dependent deviations from general relativity using Gaussian process regression. Leveraging the flexibility of this method, we analyze both simulated data and real events from the LIGO-Virgo-KAGRA public catalog. We demonstrate the ability of our approach to detect and quantify waveform deviations across the parameter space. Furthermore, we show that the method can identify stochastic (non-deterministic) deviations, potentially arising from environmental effects or subdominant unmodeled physics. As gravitational-wave tests of strong gravity advance in precision, our framework provides a principled approach to constrain modified gravity and to mitigate contamination from astrophysical or instrumental systematics.

    ↳ gr-qchep-ph1 citation
25. 25*

    Historical origins of quantum entanglement in particle physics

    Yu Shi🇨🇳

    In this paper, the historical origins of quantum entanglement in particle physics are systematically and thoroughly investigated. 1957, Bohm and Aharonov noted that the Einstein-Podolsky-Rosen correlation had been experimentally realised in the 1949 experiment of Chien-Shiung Wu and Shaknov. This was the first time in history that spatially separated quantum entanglement was explicitly realised in a controlled experiment. Wheeler first proposed such an experiment as a test of quantum electrodynamics, but his calculation was in error; the correct theoretical calculations came from Ward and Price, as well as from Snyder, Pasternack and Hornbostel, and the result was in accordance with Yang's 1949 selection rule. After the publication of Bell's inequality in 1964, it was considered whether it could be tested by using the Wu-Shaknov experiment. This gave an impetus to the field, and a new experiment was done by Wu's group, though it was not successful as a test of Bell inequality violation. In 1957, Tsung-Dao Lee, Reinhard Oehme and Chen Ning Yang established the quantum mechanical description of the kaons and found that the neutral kaon is a two-state system. In 1958, based on an approach similar to Yang's 1949 selection rule, Goldhaber, Lee and Yang were the first to write down the entangled states of kaon pairs, in which a single kaon can be charged or neutral. This gave, for the first time, quantum entanglement of internal degrees of freedom of high-energy particles other than photons. In 1960, as unpublished work, Lee and Yang discussed the consequences of quantum entanglement of neutral kaon pairs. We also describe several physicists in the past, especially Ward. A Chinese version of this paper was published in early 2023.

    ↳ physics.hist-phhep-exhep-phquant-phInternational Journal of Modern Physics A…·3 citations
26. 26*

    Testing the cosmic distance duality relation with baryon acoustic oscillations and supernovae data

    Tian-Nuo Li🇺🇸 · Guo-Hong Du🇺🇸 · Peng-Ju Wu🇨🇳 · Jing-Zhao Qi🇺🇸 · Jing-Fei Zhang🇺🇸 · Xin Zhang🇺🇸

    One of the most fundamental relationships in modern cosmology is the cosmic distance duality relation (CDDR), which describes the relationship between the angular diameter distance ($D_{\mathrm{A}}$) and the luminosity distance ($D_{\mathrm{L}}$), and is expressed as: $\eta (z)=D_{\mathrm{L}}(z)(1+z{)}^{-2}/D_{\mathrm{A}}(z)=1$. In this work, we conduct a comprehensive test of the CDDR by combining baryon acoustic oscillation (BAO) data from the SDSS and DESI surveys with type Ia supernova (SN) data from PantheonPlus and DESY5. We utilize an artificial neural network approach to match the SN and BAO data at the same redshift. To explore potential violations of the CDDR, we consider three different parameterizations: (i) $\eta (z)=1+{\eta }_{0}z$; (ii) $\eta (z)=1+{\eta }_{0}z/(1+z)$; (iii) $\eta (z)=1+{\eta }_0\ln (1+z)$. Our results indicate that the calibration of the SN absolute magnitude $M_{\mathrm{B}}$ plays a crucial role in testing potential deviations from the CDDR, as there exists a significant negative correlation between ${\eta }_0$ and $M_{\mathrm{B}}$. For PantheonPlus analysis, when $M_{\mathrm{B}}$ is treated as a free parameter, no evidence of CDDR violation is found. In contrast, fixing $M_{\mathrm{B}}$ to the $M_{\mathrm{B}}^{D20}$ prior with $-19.230\pm 0.040$ mag leads to a deviation at approximately the $2\sigma$ level, while fixing $M_{\mathrm{B}}$ to the $M_{\mathrm{B}}^{B23}$ prior with $-19.396\pm 0.016$ mag remains in agreement with the CDDR. Furthermore, overall analyses based on the SDSS+DESY5 and DESI+DESY5 data consistently show no evidence of the deviation from the CDDR.

    ↳ astro-ph.COgr-qchep-phEPJC(2025)·31 citations
27. 27*

    Gravity and the Higgs boson mass

    Carlo Branchina🇮🇹 · Vincenzo Branchina🇮🇹 · Filippo Contino🇮🇹 · Riccardo Gandolfo🇮🇹 · Arcangelo Pernace🇮🇹

    According to usual calculations in quantum field theory, both in flat and curved spacetime, the mass $m^2$ of a scalar particle is quadratically sensitive to the ultimate scale of the theory, the UV physical cutoff $\Lambda$. In the present work, paying attention to the path integral measure and to the way $\Lambda$ is introduced, we calculate the one-loop effective action ${\Gamma }^{1l}$ for a scalar field on a non-trivial gravitational background. We find that $m^2$ presents only a (mild) logarithmic sensitivity to $\Lambda$. This is obtained without resorting to a supersymmetric embedding of the theory, nor to regularization schemes (as dimensional or zeta-function regularization) where power-like divergences are absent by construction. In view of the results of the present work, we finally speculate on the way the Minkowski limit should be approached.

    ↳ hep-thgr-qchep-ph8 citations
28. 28*

    Magnetic monopoles with an internal degree of freedom

    Petr Beneš🇨🇿 · Filip Blaschke🇨🇿

    We consider a class of spontaneously broken $SU(2)$ gauge theories with adjoint scalar and look for exact magnetic monopole solutions in the Bogomol'nyi-Prasad-Sommerfield (BPS) limit. We find that some of the resulting solutions exhibit a new internal degree of freedom (a moduli space parameter) that controls the energy density profile of the monopole while keeping the total energy (mass) constant.

    ↳ hep-thcond-mat.otherhep-phnlin.PSPTEP(2026)·1 citation
29. 29*

    Exotic Dark Matter and the DESI Anomaly

    Matteo Braglia🇺🇸 · Xingang Chen🇺🇸 · Abraham Loeb🇺🇸

    Exotic dark matter (EDM) refers to a dark matter species whose equation of state deviates from zero at late times. This behavior enables it to model a variety of non-standard late-time cosmologies, offering alternatives to various dark energy (DE) models, especially when the DE sector violates the null energy condition. In this work, by fitting to CMB, BAO, and Supernovae (SNe) data and comparing models in a Bayesian approach, we show that simple models of exotic dark matter are statistically comparable to the $w_0{w}_a$CDM DE model in explaining the recent anomaly in the late-time cosmological evolution suggested by DESI and supernova observations, although in both classes of models the evidence against the $\Lambda$CDM model only appears when the DES-Y5 or Union3 SNe dataset is included. The value of $H_0$ remains similar to that in the DE model, except in the no-SNe case, where the DE model predicts lower values than $\Lambda$CDM, thereby worsening the Hubble tension, whereas the EDM models yield values closer to that of $\Lambda$CDM, albeit with larger uncertainty. In addition, the EDM models predict a drastically different energy budget for the present-day universe compared to the standard model, and provide an explanation for a coincidence problem in the DE-model explanation of the DESI anomaly.

    ↳ astro-ph.COhep-phhep-thJCAP(2025)·44 citations
30. 30*

    Strangeon Matter: from Stars to Nuggets

    Haoyang Qi🇨🇳 · Renxin Xu🇨🇳

    The fact that strange sea quarks are abundant in the nucleons, but with zero net strangeness, is of great importance for understanding the nature of matter condensed by the strong interaction, particularly in the context of the ``gigantic nucleus'' formed by the gravitational collapse of an evolved massive star. We hypothesize that the basic unit of bulk strong matter with the light-flavor symmetry of valence quarks is ``strangeon'', which is the counterpart of the nucleon found in atomic nuclei. In addition to strangeon stars (SnSs) with large baryon number of $A\approx 10^{57}$, strange nuggets (SnNs) with $A\gtrsim 10^{10}$ could also exist in the Universe. Both the SnS and the SnN are explained, with attention to their observational evidence.

    ↳ astro-ph.HEhep-phnucl-thUniverse(2025)·1 citation
31. 31*

    Testing signatures of phantom crossing through full-shape galaxy clustering analysis

    Emanuelly Silva🇧🇷 · Rafael C. Nunes🇧🇷

    Recent observations of baryon acoustic oscillations (BAO) from the Dark Energy Spectroscopic Instrument (DESI) survey, when combined with measurements of the cosmic microwave background (CMB) and Type Ia supernovae (SNIa), provide compelling evidence for a phantom crossing at late times, along with statistically significant deviations from the standard $\Lambda$CDM model. In this work, we investigate the role of redshift-space galaxy clustering data by employing the pre-reconstruction full-shape (FS) galaxy power spectrum from the Baryon Oscillation Spectroscopic Survey (BOSS) data release 12 (DR12) sample. This dataset is analyzed in combination with BAO measurements from DESI data release 2 (DR2) and various SNIa samples. Our analysis demonstrates that the joint combination of these datasets can yield deviations from $\Lambda$CDM at a significance level of up to $\sim 5\sigma$, suggesting strong indications that the dark energy equation of state parameter $w(z)$ may have crossed the phantom divide ($w=-1$) in the redshift range $z\sim 0.4$-$0.5$. The precise location and strength of this crossing depend on the adopted theoretical parameterizations. Importantly, our results reveal that this trend persists even in the absence of CMB data, underscoring the robustness of the FS power spectrum as a powerful and independent probe for testing dark energy models and for distinguishing between competing cosmological scenarios.

    ↳ astro-ph.COgr-qchep-phJCAP(2025)·53 citations
32. 32*

    Comment to "The asymptotically-free gauge theories"

    Giacomo Cacciapaglia🇫🇷 · Aldo Deandrea🇫🇷 · Francesco Sannino🇩🇰

    The recent paper "The asymptotically-free gauge theories" by Ben Gripaios and Khoi Le Nguyen Nguyen [arXiv:2507.12348] presents a proposed classification of gauge theories valid down to arbitrarily short scales. In this comment, we aim to clarify several points and address some statements that may be misleading. We also provide additional context by discussing relevant prior literature and existing classifications.

    ↳ hep-thhep-ph0 citations
33. 33*

    Spectral BBGKY: a scalable scheme for nonlinear Boltzmann and correlation kinetics

    Xingjian Lu🇨🇳 · Shuzhe Shi🇨🇳

    The Bogoliubov-Born-Green-Kirkwood-Yvon (BBGKY) hierarchy provides a time-reversal-symmetric framework for describing the nonequilibrium evolution of many-body systems. Despite the success of Boltzmann-based numerical approaches, systematically extending beyond this lowest-order truncation to the full nonlinear BBGKY hierarchy remains a major challenge. Moreover, even at the Boltzmann level, accurately treating the nonlinear collision term still presents significant difficulties. Here we propose the spectral BBGKY hierarchy, an analytically equivalent and numerically tractable reformulation of the conventional BBGKY hierarchy. The spectral formulation reduces the original 6n-dimensional phase-space problem to the evolution of spectral coefficients over the 3n-dimensional coordinate space. We also develop an analytic scheme for computing the collision integrals, which achieves high accuracy and removes the need for ensemble averaging over repeated stochastic evolutions from the same initial state. The scheme evaluates the full eight-fold integral exactly for massless particles, and reduces it to a three-fold one for massive particles. The validity of the spectral BBGKY hierarchy is verified through conservation law analysis, comparison with an analytical solution, convergence tests, and analysis of spectral coefficient leakage. At minimal truncation, the spectral BBGKY yields a spectral nonlinear Boltzmann equation that captures full dynamics with a computational cost comparable to that of linearized approaches. When extended to higher-order truncations, the spectral BBGKY hierarchy provides a flexible framework for studying multiparticle correlations. This framework advances our ability to investigate the early thermalization puzzle in relativistic heavy-ion collisions and to elucidate the applicability of hydrodynamics at remarkably early stages of quark-gluon plasma evolution.

    ↳ nucl-thcond-mat.stat-mechhep-phPRC(2026)·7 citations
34. 34*

    Probing of EoS with clusters and hypernuclei

    Yingjie Zhou🇩🇪 · Susanne Glässel🇩🇪 · Yue-Hang Leung🇩🇪 · Viktar Kireyeu🇷🇺 · Jiaxing Zhao🇩🇪 · Hui Liu🇨🇳 · Christoph Blume🇩🇪 · Iouri Vassiliev🇩🇪 · Vadim Voronyuk🇷🇺 · Michael Winn🇫🇷 · Norbert Herrmann🇩🇪 · Yaping Wang🇨🇳 and 3 other authors

    The study of the nuclear equation-of-state (EoS) is a one of the primary goals of experimental and theoretical heavy-ion physics. The comparison of recent high statistics data from the STAR Collaboration with transport models provides a unique possibility to address this topic in a yet unexplored energy domain. Employing the microscopic N-body Parton-Hadron-Quantum-Molecular Dynamics (PHQMD) transport approach, which allows to describe the propagation and interactions of hadronic and partonic degrees of freedom including cluster and hyper-nucleus formation and dynamics, we investigate the influence of different EoS on bulk observables, the multiplicity, $p_T$ and rapidity distributions of protons, $\Lambda$s and clusters up to A=4 as well as their influence on the collective flow. We explore three different EoS: two static EoS, dubbed 'soft' and 'hard', which differ in the compressibility modulus, as well as a soft momentum dependent EoS. We find that a soft momentum dependent EoS reproduces most baryon and cluster observables, including the flow observables, quantitatively, however, hard EOS show a similar trend.

    ↳ nucl-thhep-phPRC(2026)·11 citations
35. 35*

    Deciphering the dynamics of nuclear collisions with elongated structure of ${}^{20}$Ne

    Deependra Sharma🇺🇸 · Arpit Singh🇮🇳 · Sadhana Dash🇮🇳

    We investigate the role of intrinsic nuclear geometry of ${}^{20}$Ne nucleus in particle production in small collision systems. Discrete geometrical representations of ${}^{20}$Ne, including bi-pyramidal $\alpha$-cluster structure in two different configurations along with NLEFT configurations, are implemented within the Monte Carlo Pythia8/Angantyr framework. The resulting particle production observables in ${}^{20}$Ne-${}^{20}$Ne collisions at $\sqrt{s_{NN}}$ = 5.36 TeV are systematically compared with those obtained using conventional Woods-Saxon description as well as with the available hydrodynamic model calculations. We investigate the sensitivity of charged particle multiplicity, transverse momentum distributions and mean transverse momentum $⟨p_T⟩$ to nuclear geometry, $\alpha$-clustering, and orientation effects of ${}^{20}$Ne nucleus. While explicit clustering and orientation dependence lead to a noticeable modifications in final state charged particle multiplicity, their impact on transverse momentum spectra and $⟨p_T⟩$ remain modest in central collisions. The results highlight the role of intrinsic nuclear geometry and specific orientation of the colliding nuclei, providing insight into the dynamics of small systems in non-hydrodynamic particle production framework.

    ↳ nucl-thhep-phhep-th1 citation

* 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.