Tue·Jan 27, 2026Tuesday·January 27, 2026

1. 01*

   Fermionic Dark Matter and New Scalar Production in $e^{+}{e}^{-}\to H^{+}{H}^{-}$ at Colliders

   Asmaa AlMellah🇹🇼 · Faeq Abed🇪🇬 · Gaber Faisel🇹🇼

   We investigate the pair production process $e^{+}{e}^{-}\to H^{+}{H}^{-}$ in the framework of the scotogenic model. The production mechanism receives contributions at tree level from photon and $Z$-boson exchange, as well as from $t$-channel exchange of the new singlet right-handed fermions $N_{1,2,3}$. where neutrino masses are generated radiatively and one of the singlet right-handed fermions serves as a viable dark matter candidate. We evaluate the individual contributions of these diagrams and compute the total production cross section after imposing all relevant theoretical and experimental constraints on the model parameters, including those associated with dark matter relic abundance and direct detection limits. Our results demonstrate that the dominant contribution to the cross section originates from the exchange of the singlet fermions $N_{1,2,3}$, particularly from the dark matter component of the spectrum. In addition, we examine the dependence of the cross section on the center-of-mass energy for several benchmark scenarios in the allowed parameter space. These predictions can be probed at future high-energy $e^{+}{e}^{-}$ colliders, providing a sensitive test of the scotogenic framework and the role of fermionic dark matter, as well as enabling more stringent constraints on the model parameters.

   hep-phhep-ex0 citations
2. 02*

   Probing the $\gamma {\gamma }^{\ast }\to {\eta }^{(\prime )}$ Transition Form Factors with Newly Derived ${\eta }^{(\prime )}$-Meson Light-Cone Distribution Amplitudes

   Dan-Dan Hu🇨🇳 · Xing-Gang Wu🇨🇳 · Yu-Jie Zhang🇨🇳 · Hai-Bing Fu🇨🇳 · Tao Zhong🇨🇳

   In the present work, we analyze the properties of the transition form factors (TFFs) for the $\gamma {\gamma }^{\ast }\to {\eta }^{(\prime )}$ process, employing the ${\eta }^{(\prime )}$-meson light-cone distribution amplitude (LCDA) derived within the light-cone sum rule framework. To this end, we adopt the quark-flavor mixing scheme for the ${\eta }^{(\prime )}$ meson, and compute the TFFs by systematically incorporating transverse-momentum corrections and contributions beyond the leading Fock state. We utilize light-cone harmonic oscillator models to parameterize the longitudinal and transverse behavior of the leading-twist light-cone wavefunction, for which the corresponding LCDA exhibits a unimodal profile. We further examine the potential contributions of intrinsic charm components to the scaled TFFs $Q^2{F}_{\eta \gamma }(Q^2)$ and $Q^2{F}_{{\eta }^{\prime }\gamma }(Q^2)$. Leveraging a range of values for the decay constant $f_{{\eta }_{c_0}}$ and implementing the $\eta$-${\eta }^{\prime }$-${\eta }_c$ and $\eta$-${\eta }^{\prime }$-$G$-${\eta }_c$ mixing mechanisms accordingly, together with the recently updated mixing angles, we investigate the impact of the intrinsic $c\bar{c}$ and gluonic component on these observables. In high-$Q^2$ regime, $Q^2{F}_{{\eta }^{\prime }\gamma }(Q^2)$ exhibits a marked increase in sensitivity to the charm quark component, whereas $Q^2{F}_{\eta \gamma }(Q^2)$ becomes notably stabilized. A detailed discussion of ${\chi }^2/d.o.f$ and $p$-values indicates that the intrinsic charm quark component is important and yields a substantial, non-negligible contribution across the entire $Q^2$ range.

   hep-phPRD(2026)·1 citation
3. 03*

   Non-Abelian Recoil Geometry and Infrared Holonomies in Heavy-Quark Transitions

   Jorge Gamboa🇨🇱 · Natalia A. Tapia Arellano🇺🇸

   We propose a geometric formulation of heavy-quark transitions in which infrared-dressed states are adiabatically transported in the multidimensional recoil space and acquire Berry holonomies. Within this framework, single-step decays are governed by an abelian geometric phase and reproduce the standard Isgur-Wise behaviour, while sequential decays probe genuinely non-Abelian holonomies associated with a two-dimensional recoil space. The resulting geometric structure correlates different decay channels and provides a unified interpretation of mixing effects and quasi-degenerate states in heavy-quark phenomenology. This approach suggests that several long-standing puzzles arise as geometric consequences of infrared dressing rather than as accidental features of the microscopic dynamics.

   hep-phhep-th0 citations
4. 04*

   The calculation of 2-loop self-energy diagrams by the sector decomposition

   Kiyoshi Kato🇯🇵

   Detailed description of the calculation of the 2-loop self-energy for a scalar particle is presented. By employing a simple sector decomposition method, the ultraviolet divergent part is efficiently separated from the finite part. The resulting expression can be used for both analytic and numerical computation to renormalize the divergence and to provide finite results for physics.

   hep-phKogakuin Daigaku Kenkyuronso, vol.62-2, p…·0 citations
5. 05*

   Dynamical study of $\pi N\to \pi \pi N$ reactions revisited

   H. Kamano🇯🇵 · T.-S. H. Lee🇺🇸

   Using the Argonne National Laboratory-The University of Osaka (ANL-Osaka) DCC model of meson-nucleon reactions, we extend the study of Phys. Rev. C 79, 025206 (2009) and Phys. Rev. C 88, 045203 (2013) to predict the cross sections of the $\pi N\to \pi \pi N$ reactions. The model was constructed by fitting only the two-body reactions: $\pi N,\gamma N\to \pi N,\eta N,K\Lambda ,K\Sigma$. Thus, the results for $\pi N\to \pi \pi N$ presented here are predictions of the ANL-Osaka DCC model, which serve to examine the extent to which the forthcoming data from J-PARC can be described. This study provides information for improving the extraction of nucleon resonances that have large decay widths to $\pi \pi N$ states. We present results for the total cross sections, invariant mass distributions, and angular distributions. We also identify the observables and energy regions where the higher mass nucleon resonances in the $S_{31}$, $P_{33}$, $D_{33}$, $F_{37}$, $D_{13}$, $D_{15}$, and $F_{15}$ partial waves can be most effectively investigated.

   hep-phnucl-th2 citations
6. 06*

   The Dirac Majorana Confusion Theorem in the Presence of Flavor-Changing Neutral Currents: A CP-Filter Mechanism

   David Delepine (1)🇲🇽 · A. Yebra (1) ((1) Division de Ciencias e Ingenierias, Universidad de Guanajuato)🇲🇽

   The Practical Dirac Majorana Confusion Theorem(PDMCT) asserts that phenomenological differences between Dirac and Majorana neutrinos are kinematically suppressed by (neutrino mass/E)^2 in lepton number conserving processes. The PDMCT relies on standard lefthanded neutrino interactions, as in the SM, in which case Dirac and Majorana neutrinos are experimentally indistinguishable in lepton-number-conserving processes. Our scenario explicitly goes beyond these assumptions by introducing a neutral vector boson Zprime with CP-violating, flavor changing neutral current (FCNC) couplings, which generate observable Dirac Majorana differences while remaining fully consistent with the PDMCT. In strict accordance with the PDMCT, Fermi Dirac statistics dictate that the flavor-diagonal vector current identically vanishes for Majorana neutrinos.For non diagonal transitions, the Majorana condition strictly forbids the real (CP conserving) component of the vector interaction, leaving only a imaginary coupling. As a consequence, the observable difference in inclusive scattering cross-sections between Dirac and Majorana neutrinos is driven entirely by the FCNC CP-violating couplings. We apply these results to Coherent Elastic Neutrino-Nucleus Scattering (CEnuNS), showing that for spin-zero targets, the distinguishability of the neutrino's nature is determined by the CP structure of the new interaction.

   hep-phPRD(2026)·0 citations
7. 07*

   Gluon Generalized TMD signatures at the EIC from exclusive heavy (axial-)vector meson production

   Shohini Bhattacharya🇺🇸 · David DeAngelo🇺🇸 · Lei Yang🇨🇳 · Duxin Zheng🇨🇳 · Jian Zhou🇨🇳

   Potential experimental signatures of gluon generalized transverse momentum-dependent distributions (GTMDs) are proposed via exclusive heavy (axial-)vector meson production in lepton-proton collisions. Within the framework of collinear twist-3 factorization, we show that specific azimuthal-angle-dependent observables can provide sensitivity to the gluon GTMDs $F_{1,4}^g$ and $G_{1,1}^g$, which are related to partonic orbital angular momentum and spin-orbit correlations, respectively. These functions represent a unique sector of nucleon structure with no counterparts in the generalized parton distribution or transverse-momentum-dependent frameworks. We show that interference between different virtual-photon polarizations leads to distinct azimuthal modulations, including the polarization-independent $\cos 2\varphi$ and polarization-dependent $\sin 2\varphi$ terms, with $\varphi$ defined as the angle between the lepton scattering plane and the hadron production plane. These observables provide signatures of the elusive gluon GTMDs $F_{1,4}^g$ and $G_{1,1}^g$, opening a new channel to access the spin structure of the nucleon at the future Electron-Ion Collider.

   hep-phhep-exPRD(2026)·9 citations
8. 08*

   Production of high-spin ${\omega }_J/{\rho }_J$ ($J=2,3,4,5$) mesons in ${\pi }^{-}p$ reactions

   Ting-Yan Li🇨🇳 · Zi-Yue Bai🇨🇳 · Xiang Liu🇨🇳

   In this work, we perform a comprehensive investigation of the production of high-spin ${\omega }_J$ and ${\rho }_J$ mesons ($J=2,3,4,5$) in ${\pi }^{-}p$ reactions using an effective Lagrangian approach. By constructing the relevant $t$-channel processes and calibrating the model with a single adjustable parameter fitted to existing data, we successfully reproduce the measured total and differential cross sections for the $J=3$ states ${\omega }_3(1670)$ and ${\rho }_3(1690)$. Within the same framework, we predict the production cross sections for their lower- and higher-spin partners: ${\omega }_2(1975)$, ${\rho }_2(1940)$, ${\omega }_4(2250)$, ${\rho }_4(2230)$, ${\omega }_5(2350)$, and ${\rho }_5(2350)$. Our results show that these states exhibit measurable cross sections with characteristically forward-peaked angular distributions, underscoring their strong potential for observation in future $\pi p$ meson-beam experiments.

   hep-phhep-exnucl-exnucl-thPRD(2026)·1 citation
9. 09*

   Liberation of dynamical quarks at high temperature

   Vladimir Voronin🇷🇺

   Confinement of dynamical fields can be attributed to the absence of corresponding asymptotic states. Thermodynamical properties of such system are more appropriately formulated in terms of collective excitations of these fields, if they appear as particles. This mechanism is investigated in the mean-field quark model of confinement and hadronization. In this model, deconfinement and restoration of chiral symmetry happen simultaneously at certain critical temperature.

   hep-ph0 citations
10. 10*

    Tensor form factors of decuplet hyperons in QCD

    Z. Asmaee🇮🇷 · K. Azizi🇮🇷

    Tensor form factors encode essential information about the internal spin structure and tensor dynamics of baryons. In this work, we investigate the tensor form factors of the baryon hyperons ${\Omega }^{-}$, ${\Sigma }^{\ast +}$, and ${\Xi }^{\ast -}$ within the framework of QCD sum rules. The complete set of tensor form factors is numerically evaluated in the momentum transfer region $0<Q^2<10{\text{GeV}}^2$. In addition, the quark tensor charges of the considered hyperons are extracted in the forward limit. The results provide new non-perturbative insight into the tensor structure and spin content of spin-$3/2$ baryons and offer valuable theoretical input for future phenomenological analyses and experimental studies.

    hep-phhep-exhep-latPRD(2026)·2 citations
11. 11*

    Theoretical study of $f_0(980)$, $a_0(980)$ and $\Xi (1/2^{-})$ in the process ${\Xi }_c^{+}\to {\Sigma }^{+}{K}^{+}{K}^{-}$

    Ruitian Li🇨🇳 · Xuan Luo🇨🇳 · Hao Sun🇨🇳

    We employed the chiral unitarity approach to investigate the decay process ${\Xi }_c^{+}\to {\Sigma }^{+}{K}^{+}{K}^{-}$, by considering that the low lying nucleon resonance $\Xi (1/2^{-})$ and the low lying scalar meson $f_0(980)$ and $a_0(980)$ that could be dynamically generated through $S$-wave pseudoscalar meson-octet baryon and the $S$-wave pseudoscalar meson-pseudoscalar meson interactions, respectively. In the invariant mass distributions of ${\Sigma }^{+}{K}^{-}$ and $K^{+}{K}^{-}$, we observe a distinct peak structure associated with the resonant state $\Xi (1/2^{-})$ and a bit enhancement near the $K^{+}{K}^{-}$ threshold that is corresponding to the mesons $f_0(980)$ and $a_0(980)$, respectively. Consequently, we recommend more precise experimental measurements of this process in the future.

    hep-phPRD(2026)·0 citations
12. 12*

    Low-energy scattering of the $J/\psi \pi$ and $J/\psi K$ system

    Jiang Yan🇨🇳 · Xiong-Hui Cao🇨🇳 · Meng-Lin Du🇨🇳 · Feng-Kun Guo🇨🇳

    We investigate the low-energy interactions between the charmonium state $J/\psi$ and the light pseudoscalar mesons ($\pi$ and $K$) within the framework of dispersion relations. We demonstrate that the symmetry-breaking terms in the chiral Lagrangian induce mixing between the bare charmonium fields, necessitating a diagonalization procedure to correctly identify the physical $J/\psi$ and ${\psi }^{\prime }$ states. Using the resulting diagonalized Lagrangian, we construct the crossed-channel amplitudes for $J/\psi J/\psi \to \mathcal{P}\bar{\mathcal{P}}$ and incorporate the $\pi \pi$ and $K\bar{K}$ rescattering effects through dispersion relations. This framework is used consistently both in the phenomenological extraction of the transition parameters from ${\psi }^{\prime }\to J/\psi \pi \pi$ and in the continuation of the crossed amplitudes to the near-threshold $J/\psi \mathcal{P}(\mathcal{P}=\pi ,K)$ region. As a result, we determine both the scattering lengths and the effective ranges. We obtain the upper-bound estimates $a_{J/\psi \pi }\lesssim -0.0037$~fm and $a_{J/\psi K}\lesssim -0.049$~fm, where the negative sign indicates an attractive interaction without a bound state in our convention. Our results show that the $J/\psi K$ interaction is moderately enhanced relative to the pion channel, driven by explicit chiral symmetry breaking. Furthermore, a quantitative comparison of the coupled-channel mechanism, where $J/\psi \pi$ and $J/\psi K$ couple to open-charm channels, reveals that both $J/\psi \pi$ and $J/\psi K$ scatterings are predominantly governed by the soft-gluon exchange mechanism.

    hep-phPLB(2026)·3 citations
13. 13*

    Heavy Quarkonium Spectrum and Decay Constants from a Neural-Network-Based Holographic Model

    Yu Zhang🇨🇳 · Xun Chen🇨🇳 · Miguel Angel Martin Contreras🇨🇳

    We present a data-driven inverse construction of the dilaton field in a bottom-up AdS/QCD description of heavy vector quarkonia. Instead of adopting an \emph{ad hoc} analytic ansatz, we use a multilayer perceptron to learn \(\Phi'(z)\) as a smooth function of the holographic coordinate, with \(\Phi(0)=0\) imposed to ensure ultraviolet consistency. The dilaton and its derivatives obtained by automatic differentiation generate the holographic potential \(U(z)\), and the associated Schrödinger-like equation is discretized and diagonalized to extract the low-lying eigenmodes. Masses and decay constants are then evaluated from the eigenvalues and the near-boundary behavior of the bulk-to-boundary modes. Training on PDG data for charmonium and bottomonium yields a non-quadratic dilaton profile that resolves the longstanding difficulty of simultaneously reproducing both the heavy-quarkonium spectrum and the monotonic suppression of leptonic decay constants with radial excitation. The combined fit achieves RMS deviations of \(1.26\%\) (charmonium) and \(3.32\%\) (bottomonium). This work establishes neural-network reconstruction as a flexible tool for holographic modeling and provides a basis for future extensions incorporating additional channels, lattice constraints, or finite-temperature backgrounds.

    hep-phPRD(2026)·6 citations
14. 14*

    Radiative generation of chiral vector operators in $b\to s\nu \bar{\nu }$ transition

    Xin-Shuai Yan🇨🇳 · Wen-Feng Liu🇨🇳 · Qin Chang🇨🇳 · Ya-Dong Yang🇨🇳

    The recent Belle II evidence for $B^{+}\to K^{+}\nu \bar{\nu }$, combined with a suppressed branching fraction ratio $R\equiv \mathcal{B}(B^0\to K^{\ast 0}\nu \bar{\nu })/\mathcal{B}(B^{+}\to K^{+}\nu \bar{\nu })$, necessitates new physics contributing to both left- and right-handed vector operators. We perform a systematic topological classification of one-loop completions that radiatively generate both operators without tree-level mediation, and construct two minimal benchmark scenarios: a scalar-rich model and a fermion-rich model. Evaluating these frameworks under specific benchmark mass schemes and four distinct flavor structures, we find a generic anti-correlation where enhancing one decay channel typically suppresses the other. A notable exception is a decoupled flavor configuration within the scalar-rich model, which yields simultaneous constructive interference, reducing $R$ by $4.22\%$ while satisfying all complementary flavor bounds. Under a universal coupling assumption, the scalar-rich model yields exact cancellation in the charged mode, highlighting the non-trivial interplay between flavor structure and loop-generated Wilson coefficients.

    hep-ph0 citations
15. 15*

    Reconstructing Toponium using Recursive Jigsaw Reconstruction

    Aman Desai🇦🇺 · Amelia Lovison🇦🇺 · Paul Jackson🇦🇺

    The results from the ATLAS and CMS experiment at the Large Hadron Collider indicate the existence of a top-quark pair bound state near the $\text{ttbar}$ threshold region. We present a method relying on Recursive Jigsaw Reconstruction to reconstruct the toponium bound state at the $\text{ttbar}$ threshold region. We propose incorporating two variables in the analysis that can improve sensitivity to the toponium signal. Our results indicate that this method may be useful to gain additional insights into the physics phenomenology of the $\text{ttbar}$ threshold region.

    hep-phJ.Subatomic Part.Cosmol.(2026)·0 citations
16. 16*

    Revisiting $\mu$-$e$ conversion in $R$-parity violating SUSY

    Yu-Qi Xiao🇨🇳 · Xiao-Gang He🇨🇳 · Hong-Yi Niu🇨🇳 · Rong-Rong Zhang🇨🇳

    The $\mu$-$e$ conversion process is one of the most powerful ways to test lepton-flavor-violating (LFV) interactions involving charged leptons. The standard model with massive neutrinos predicts an extremely low rate for $\mu$-$e$ conversion, making this process an excellent probe for testing LFV arising from new physics. Among many theoretical models that can induce LFV, the Supersymmetric model with R-parity violating interactions is one of the most studied for $\mu$-$e$ conversion. In this work, we revisit trilinear R-parity violating interactions for $\mu$-$e$ conversion, considering renormalization group (RG) running effects from high to low energy scales. The $\mu$-$e$ conversion, $\mu \to e\gamma$, and $\mu \to eee$ experimental data are compared to give upper limits on the relevant 15 combinations of the trilinear ${\lambda }^{\prime }$ couplings and 6 combinations of the $\lambda$ couplings, certain of which are underexplored in previous studies. We find that RG running effects influence the limits by no more than 30\% in most cases, but can improve constraints by $\sim$80\% in certain combinations, which cannot be neglected. In the near future, COMET and Mu2e are expected to begin data-taking and aim to provide the most stringent constraints on $\mu$-$e$ conversion. These next-generation $\mu$-$e$ experiments have the ability to give much more comprehensive examinations on most trilinear coupling combinations than the $\mu \to e\gamma$ and $\mu \to 3e$ decay experiments. The $\mu$-$e$ experiments will not only deepen our understanding of LFV but also provide a crucial way to examine the underlying new physics contributions.

    hep-phJHEP(2026)·0 citations
17. 17*

    A particle on a ring or: how I learned to stop worrying and love $\theta$-vacua

    Mohammad Aghaie🇯🇵 · Ryosuke Sato🇯🇵

    Recently, Ai, Cruz, Garbrecht, and Tamarit (arXiv:2001.07152, arXiv:2404.16026, arXiv:2511.04216) claimed that the strong CP problem can be avoided by adopting a particular order of limits in the Euclidean path integral, in which the spacetime volume is taken to infinity before summing over all topological sectors. We critically examine this proposal using exactly solvable examples of one-dimensional quantum mechanics on a ring, namely the quantum rotor and the quantum pendulum. These systems provide fully controlled settings with known $\theta$-dependent spectra. We find that the ACGT procedure fails to reproduce the correct energy spectrum. Since the spectrum is a direct physical observable, this result demonstrates that the proposed order of limits cannot be justified and conclusions about CP conservation in QCD cannot be based on this prescription alone.

    hep-phhep-thquant-phJHEP(2026)·9 citations
18. 18*

    Probing electromagnetic moments of the tau lepton in PbPb collisions at the FCC-hh

    S.C. İnan🇹🇷 · A.V. Kisselev🇷🇺

    A production of a pair of tau leptons in PbPb collisions at the FCC-hh collider is examined. The 95\% C.L. exclusion limits, as well as 3$\sigma$ and 5$\sigma$ sensitivity limits on the anomaly magnetic moment of the tau lepton $a_{\tau }$ and its electric dipole moment $d_{\tau }$ are obtained. A comparison with bounds on $a_{\tau }$ and $d_{\tau }$ for other future colliders are given.

    hep-phhep-ex1 citation
19. 19*

    Analysis of freeze-in scenario with a scalar Leptoquark and a scalar Dark Matter

    Joydeep Roy🇮🇳

    Dark Matter relic density generation through \textit{freeze-in} mechanism where dark matter particles interact feebly with visible sector particles, is an alternative approach to well-studied and most popular \textit{freeze-out} paradigm. We study this \textit{freeze-in} scenario in the presence of a scalar leptoquark interacting with both dark matter and Standard Model particles with renormalizable interactions. We discuss the effect of the presence of such heavy particle, a scalar leptoquark with mass $\ge 1.5\text{TeV}$, in the thermal bath and subsequent relic density generation. We explore the parameter space of such framework, consisting of two masses and three dimensionless couplings. We numerically study the interaction rates and relic density as a function of these parameters and determine their values consistent with the dark matter constraints.

    hep-ph0 citations
20. 20*

    Tensor-polarized parton distribution functions for spin-1 hadrons

    S. Kumano🇨🇳

    Spin-1 hadrons contain different aspects of spin physics from the ones of the spin-1/2 nucleon because of the existence of tensor-polarized structure functions. In the charged-lepton deep inelastic scattering from a spin-1 hadron or nucleus, such as the deuteron, there are leading-twist structure functions $b_1$ and $b_2$. In addition, there exists a gluon transversity which does not exist in the spin-1/2 nucleon. In the deuteron, these observables could probe interesting dynamical aspects beyond a simple bound system of a proton and a neutron. In addition, there are recent theoretical studies on higher-twist distributions. Tensor-polarized deuteron experiments are now under preparation at the Thomas Jefferson National Accelerator Facility, so that the topic of polarized deuteron is expected to become one of exciting fields in hadron physics. This paper is a brief overview on the tensor-polarized parton distribution functions, including transverse-momentum-dependent parton distributions and fragmentation functions up to twist 4.

    hep-phhep-exhep-latnucl-ex+10 citations
21. 21*

    Testing residual-symmetry-fixed columns of $U_{\mathrm{PMNS}}$ at DUNE and T2HK with initial JUNO constraints

    Debajyoti Dutta🇮🇳 · Srubabati Goswami🇮🇳 · Monal Kashav🇮🇳 · Ketan M. Patel🇮🇳

    We study fixed-column predictions of the lepton mixing matrix that arise from residual symmetries originating in a class of discrete flavour and modular symmetries. While the recent high-precision determination of ${\sin }^2{\theta }_{12}$ by JUNO already constrains part of these predictions, the remaining ones are primarily characterized by non-trivial correlations between ${\sin }^2{\theta }_{23}$ and the Dirac CP phase ${\delta }_{\mathrm{CP}}$, which are currently only weakly constrained. This motivates a detailed investigation using next-generation long-baseline neutrino experiments. For the viable scenarios, we derive precise ${\sin }^2{\theta }_{23}$-${\delta }_{\mathrm{CP}}$ correlations and use them to generate test-event samples, marginalising over the remaining oscillation parameters. We perform detailed simulations for DUNE and T2HK, presenting allowed regions in the ${\sin }^2{\theta }_{23}$-${\delta }_{\mathrm{CP}}$ plane and evaluating the CP-violation fraction as a function of exposure. Our results show that the combined sensitivity of DUNE and T2HK provides a robust test of fixed-column lepton-mixing predictions.

    hep-phJHEP(2026)·6 citations
22. 22*

    Electric and magnetic timelike form factors of hyperons at large transfer momentum

    G. Ramalho🇰🇷 · M.T. Peña🇵🇹 · K. Tsushima🇧🇷 · Myung-Ki Cheoun🇰🇷

    There has been considerable progress in the study of the electromagnetic form factors of baryons in the timelike region, through electron-positron scattering reactions ($e^{+}{e}^{-}\to B\bar{B}$), in the last two decades. Timelike experiments reveal information about the distribution of charge and magnetism inside the hyperons that cannot be obtained in spacelike experiments (electron scattering on baryons). Motivated by the novel data, we extend to the timelike region, without any further parameter fitting, a covariant quark model developed for the spacelike region that takes into account the meson cloud excitations of the baryon cores. We use the formalism to calculate the electric ($G_E$) and magnetic ($G_M$) form factors of spin 1/2 baryons in the large square transfer momentum $q^2$ region. Our calculations are compared with the available data from CLEO and BESIII above $q^2=10$ GeV${}^2$. We conclude that our predictions for the effective form factors (combination between $G_E$ and $G_M$) are in good agreement with the $q^2>15$ GeV${}^2$ data for $\Lambda$, ${\Sigma }^{+}$, ${\Sigma }^0$, ${\Xi }^{-}$ and ${\Xi }^0$. Upcoming data for ${\Sigma }^{-}$ can be used to further test our predictions. We also compare our model calculations with the available data for ratio $|G_E/G_M|$. We conclude that the present $q^2$ data range is not large enough to test our calculations, but that a more definitive test can be performed by upcoming data above $q^2=20$ GeV${}^2$.

    hep-phhep-exhep-latnucl-exJ.Subatomic Part.Cosmol.(2026)·0 citations
23. 23*

    Nuclear effects on longitudinal-transverse structure function ratio in the deuteron

    S. Kumano🇨🇳

    Nuclear modifications of the nucleon's structure function $F_2^N$ have been investigated mainly since the discovery of the EMC nuclear effect in 1983, and there were many experimental measurements from the deuteron to a heavy nucleus. Now, the details of the modifications of $F_2^N$ are known from small $x$ to large $x$. On the other hand, it is taken as granted that a nuclear modification does not exist for the longitudinal-transverse structure function ratio $R_N=F_L^N/(2x{F}_1^N)$. However, such a nuclear modification does exist theoretically. A nucleon in a nucleus moves in any space direction, which is not necessary the longitudinal direction along the virtual-photon momentum in charged-lepton scattering. Because of this transverse Fermi motion, the longitudinal and transverse structure functions mix with the mixture probability proportional to the nucleon's transverse-momentum squared ${\vec{p}}_T^2/Q^2$. In this paper, the nuclear modifications are shown numerically for the deuteron by using a standard convolution description. The magnitude of the modifications is of the order of a few percent in the deuteron; however, they should be large in large nuclei. In handling high-energy nuclear data, such nuclear modifications need to be taken into account for a precise determination of physical quantities. Now, the longitudinal-transverse structure-function ratio and tensor-polarized experiments are under preparation for the deuteron at JLab. We hope that such effects will be confirmed experimentally for not only for the deuteron but also for larger nuclei.

    hep-phhep-exhep-latnucl-ex+10 citations
24. 24*

    Interference-induced entanglement in an effectively zero-lifetime particle pair

    Xin Wu🇨🇳 · Xinbai Li🇨🇳 · Zebo Tang🇨🇳 · Yusong Wang🇨🇳 · Wangmei Zha🇨🇳

    Quantum entanglement in high-energy collisions is often obscured by finite lifetimes, dynamical evolution, and final-state interactions, complicating the identification of genuinely quantum correlations. Ultra-peripheral heavy-ion collisions provide a clean benchmark via the Drell-S$\ddot{\mathrm{o}}\mathrm{ding}$ production of nonresonant pion pair, realizing an effectively zero-lifetime particle pair whose quantum correlations are fixed at production and remain robust against subsequent elastic scattering. The coherent superposition of photoproduction amplitudes from two indistinguishable nuclei encodes the linear polarization of quasi-real photons in the orbital motion of the pair, generating a nonfactorizable two-particle quantum state. This entanglement leaves a direct experimental imprint: a characteristic second-harmonic azimuthal modulation in momentum space arising from spin-dependent interference between the two sources. In this paper, we establish a quantitative framework for Drell-S$\ddot{\mathrm{o}}\mathrm{ding}$ pion-pair production in relativistic heavy-ion collisions and predict the magnitude and transverse-momentum dependence of the entanglement-induced azimuthal asymmetry. Our results provide experimentally accessible signatures of interference-induced entanglement and a controlled test of quantum coherence in relativistic environments.

    hep-ph1 citation
25. 25*

    Geometrical Constraints On Leptonic Unitarity Triangles

    Mathieu Guigue🇫🇷 · Lorenzo Restrepo🇫🇷

    The precision of the neutrino oscillation parameters measurements has improved and will continue to improve as the next-generation experiments become online. Beyond the more precise measurements of the mixing angles and phases used to parametrize the lepton mixing matrix, tests of its unitarity are of great interest. This paper studies how the amplitudes of the oscillation patterns can be used and combined to construct leptonic unitarity triangles.

    hep-phhep-ex1 citation
26. 26*

    Another relation among the neutrino mass-squared differences?

    I. Alikhanov🇷🇺

    Determining the absolute neutrino mass scale remains a compelling challenge in particle physics. Establishing precise mathematical connections among the neutrino masses could significantly facilitate this task and shed additional light on the underlying mass-generation mechanism. We highlight the possible existence of a simple algebraic relation between the mass-squared differences, $(\sqrt{\Delta m_{31}^2}+\sqrt{\Delta m_{21}^2})/(\sqrt{\Delta m_{31}^2}-\sqrt{\Delta m_{21}^2})=\sqrt{2}$, which exhibits excellent agreement with the central values of recent global fits of neutrino oscillation data. We investigate the implications of adopting this ansatz and how it reduces the number of independent parameters in the neutrino sector. Notably, for a vanishing ${\nu }_1$ mass, this expression directly simplifies to the elegant Fritzsch relation: $\sqrt{m_2/m_3}=\tan (\pi /8)$.

    hep-ph1 citation
27. 27*

    Thermoskyrmions

    Mikael Chala🇪🇸 · Juan Carlos Criado🇪🇸 · Luis Gil🇪🇸

    Skyrmions are stable and topologically non-trivial field configurations that behave like localized particles. They appear in the chiral effective theory for pions, where they correspond to the baryon states, and might also exist in the electroweak theory, in the presence of certain effective interactions. In this paper, focusing on toy models that capture different limits of the electroweak sector of the Standard Model (SM), we show that skyrmions not classically stable at zero temperature can be stabilized by thermal effects. This result motivates the study of skyrmions in the quantum effective action of the SM, potentially implying the existence of dark matter without new physics.

    hep-phhep-thJHEP(2026)·0 citations
28. 28*

    Drell-Yan Production of New Particles at Fixed-Target Experiments: Heavy Neutral Lepton as a Case Study

    Francis M. Burk🇺🇸 · P. S. Bhupal Dev🇺🇸 · Bhaskar Dutta🇺🇸 · Tao Han🇺🇸 · Aparajitha Karthikeyan🇺🇸 · Doojin Kim🇺🇸

    We demonstrate the sensitivity of Drell-Yan production processes from deep inelastic scattering in searches for beyond-the-Standard Model (BSM) physics at fixed-target or beam-bump experiments. We take heavy neutral leptons (HNLs) as a case study, produced from the decay of a light vector boson mediator with mass in the range of $2-20$ GeV, which itself is generated via the Drell-Yan process. The produced HNLs subsequently decay into Standard Model final states. We consider several current and future experiments, including SBND, DarkQuest, DUNE Near Detector (ND), and SHiP. Utilizing $\nu {\pi }^0$ and $\nu e^{+}{e}^{-}$ final states from HNL decays, we find that the Drell-Yan mechanism provides important contributions and significantly enhances the HNL search sensitivity, owing to the production of energetic final-state particles that are more readily detectable over the expected backgrounds. We find that at $90\%$ C.L. sensitivity, for gauge couplings $g_X\sim 10^{-2}(10^{-3})$ and kinematically accessible mass range, SBND and DarkQuest can probe the HNL flavor mixing $|U_{\ell }|\sim 3\times 10^{-4}(10^{-3})$, whereas DUNE ND and SHiP may extend the sensitivity down to the Type-I Seesaw prediction of $|U_{\ell }|\sim 10^{-5}$. Finally, for our chosen benchmark $|U_{\ell }|=10^{-3}$ outside of the current experimental constraints, with a fixed mass ratio $m_{Z^{\prime }}/m_N=2.1$, and working within the $U(1{)}_{B-L}$, $U(1{)}_{B-3L_{\tau }}$, and $U(1{)}_B$ parameter spaces, we find that both SBND and DarkQuest can probe $g_X\sim 10^{-3}$, DUNE ND can reach $g_X\sim 10^{-4}$, and SHiP can probe down to $g_X\sim 5\times 10^{-6}$. Our approach provides a powerful new technique to study HNL production at future fixed-target experiments and can readily be extended to other light BSM particle production within a broader class of dark sector models.

    hep-phhep-ex1 citation
29. 29*

    Single-wave solutions of the neutrino fast flavor system. Part II. Weak instabilities and their resonant behavior

    Damiano F. G. Fiorillo🇩🇪 · Georg G. Raffelt🇩🇪

    Flavor instabilities in dense neutrino media trigger exponential growth of flavor waves, yet their nonlinear saturation remains poorly understood. We examine a simple proxy for this effect in the form of a single-wave solution of an axially symmetric fast flavor system. When the angular crossing is shallow and the growth rate of the instability correspondingly small, the flavor wave primarily affects resonant neutrinos that move in phase with it. The evolution of these resonant neutrinos becomes periodic, undergoing cycles of full flavor reversal. They feed power into the unstable wave, and subsequently return to their initial state, draining power back out. This new flavor pendulum captures the dynamics of weak, nearly monochromatic fast flavor instabilities. Since weakly unstable distributions always exhibit a narrow range of unstable wavenumbers, our model likely describes the earliest development of a flavor instability when it first appears. When the instability is not weak, the linear phase of a single-wave excitation does not connect to a regular nonlinear solution, unless the angle distribution consists of only two beams.

    hep-phastro-ph.COastro-ph.HEJHEP(2026)·5 citations
30. 30*

    Next-to-next-to-leading power corrections to unpolarized Semi-Inclusive Deep Inelastic Scattering

    Ian Balitsky🇺🇸 · Alexei Prokudin🇺🇸

    Semi-Inclusive Deep Inelastic Scattering (SIDIS) is a key tool for exploring the three-dimensional structure of the nucleon through Transverse Momentum Dependent parton distributions and fragmentation functions. While leading-power contributions to the SIDIS cross-section are well established, next-to-leading (NLP) of order $1/Q$ and next-to-next-to-leading power (NNLP) corrections of order $1/Q^2$ to the hadronic tensor have only recently begun to be systematically investigated. These corrections are essential for the reliable phenomenology and interpretation of modern high-precision data. In recent papers by one of the authors, NNLP corrections to Drell-Yan process were derived using rapidity factorization formalism. In the present work we extend this approach to SIDIS and obtain analytic expressions for the unpolarized structure functions. We derive NNLP corrections that include convolutions of unpolarized distributions, $f_1$, with unpolarized fragmentation functions, $D_1$, and Boer-Mulders functions, $h_1^{\perp }$, with Collins fragmentation functions, $H_1^{\perp }$. We compare our results with previous formulations, provide numerical studies, confront our predictions with HERMES and COMPASS measurements, and present predictions for future experiments at Jefferson Lab and the Electron-Ion Collider.

    hep-phhep-thnucl-thJHEP(2026)·4 citations
31. 31*

    One-loop matching of the LEFT to the QCD gradient flow

    Òscar L. Crosas🇨🇭 · Peter Stoffer🇨🇭

    We present the complete one-loop matching of the baryon- and lepton-number-conserving low-energy effective field theory (LEFT) to the QCD gradient flow. Using Euclidean conventions and the background-field formulation of the gradient flow, we derive the short-flow-time expansion for the full LEFT operator basis up to mass dimension six. The matching is performed in dimensional regularization in the algebraically consistent 't Hooft-Veltman scheme, including a systematic treatment of evanescent operators and the finite counterterms required to restore chiral symmetry in the spurion sense. Keeping fully generic flavor structures, we verify the cancellation of spurious chiral-symmetry-violating terms with the known finite symmetry-restoring counterterms. This demonstrates that the gradient flow as a gauge-invariant ultraviolet regulator enables an efficient extraction of both divergent and finite counterterms in addition to the matching contributions. We provide the matching coefficients both before and after field redefinitions that remove redundant operators, as well as power-divergent mixings into lower-dimensional operators. Our results establish a consistent perturbative link between continuum LEFT calculations and gradient-flow-based lattice-QCD matrix elements, enabling precision low-energy phenomenology beyond leading-logarithmic accuracy.

    hep-phhep-exhep-latJHEP(2026)·1 citation
32. 32*

    EveNet: A Foundation Model for Particle Collision Data Analysis

    Ting-Hsiang Hsu🇹🇼 · Bai-Hong Zhou🇨🇳 · Qibin Liu🇺🇸 · Yue Xu🇺🇸 · Shu Li🇨🇳 · George Wei-Shu Hou🇹🇼 · Benjamin Nachman🇺🇸 · Shih-Chieh Hsu🇺🇸 · Vinicius Mikuni🇯🇵 · Yuan-Tang Chou🇺🇸 · Yulei Zhang🇺🇸

    While deep learning is transforming data analysis in high-energy physics, computational challenges limit its potential. We address these challenges in the context of collider physics by introducing EveNet, an event-level foundation model pretrained on 500 million simulated collision events using a hybrid objective of self-supervised learning and physics-informed supervision. By leveraging a shared particle-cloud representation, EveNet outperforms state-of-the-art baselines across diverse tasks, including searches for heavy resonances and exotic Higgs decays, and demonstrates exceptional data efficiency in low-statistics regimes. Crucially, we validate the transferability of the model to experimental data by rediscovering the ${\rm Y}$ meson in CMS Open Data and show its capacity for precision physics through the robust extraction of quantum correlation observables stable against systematic uncertainties. These results indicate that EveNet can successfully encode the fundamental physical structure of particle interactions, which offers a unified and resource-efficient framework to accelerate discovery at current and future colliders.

    ↳ hep-excs.LGhep-ph10 citations
33. 33*

    Averaging Theory and Dynamical Systems in Cosmology: A Qualitative Study of Oscillatory Scalar-Field Models

    Genly Leon🇨🇱 · Claudio Michea🇨🇱

    We study cosmological models using dynamical systems and averaging methods, encompassing flat and open FLRW geometries as well as the LRS Bianchi types I, III, and V. Under mild regularity and frequency-scaling assumptions, we obtain a near-identity conjugacy between the oscillatory flow and an averaged slow flow, with $\Vert \mathbf{x}(t)-\bar{\mathbf{x}}(t)\Vert =\mathcal{O}(H(t))$. The effective systems preserve the original asymptotics and yield geometry-dependent late-time attractor classifications. A corollary addresses the case in which the leading averaged vector field vanishes, so the system exhibits no autonomous drift at order $H^0$.

    ↳ gr-qchep-phhep-th1 citation
34. 34*

    Entanglement Enabled Tomography of Flux Tubes in (2+1)D Yang-Mills Theory

    Rocco Amorosso🇺🇸 · Sergey Syritsyn🇺🇸 · Raju Venugopalan🇺🇸

    We investigate the entangling properties of the color flux tube between a static quark-antiquark pair in pure gauge Yang-Mills theory. In earlier works, we defined a gauge-invariant flux tube entanglement entropy (FTE${}^2$), the excess entanglement entropy of a region of gluon fields that can be attributed to the color flux tube, and demonstrated that it is finite in the continuum limit. FTE${}^2$ was shown to have two contributions, one from the vibrations of the QCD string, and the other from its internal (color) degrees of freedom. In this work, we further explore the internal color component in (2+1)D Yang-Mills theory for $SU(N_c)$ gauge groups, varying $2\le N_c\le 5$. We identify a novel physical scale in the theory, the entanglement radius ${\xi }_0$. This radius characterizes the transverse extent of the flux tube that must be completely severed by an entangling region to capture the entanglement entropy of color degrees of freedom. The key feature underlying this phenomenon is its topological nature. This is revealed through systematic studies of multi-slab entangling regions in which FTE${}^2$ changes sharply when boundaries of the slabs completely cross-cut the flux tube. We find that ${\xi }_0$ increases approximately linearly with $N_c$ and is independent of both Rényi replica number and the inter-quark separation length. We also study FTE${}^2$ as a function of the entangling region's transverse displacement from the static quark pair and observe behavior consistent with a previously identified intrinsic width $\lambda$ of the flux tube, with an extracted value in agreement with the inverse mass of the lightest glueball for the gauge groups studied.

    ↳ hep-thhep-lathep-phnucl-thJHEP(2026)·11 citations
35. 35*

    Longitudinal Dynamics of Large and Small Systems from a 3D Bayesian Calibration of RHIC Top-energy Collision Data

    A. Mankolli🇺🇸 · C. Shen🇺🇸 · M. Luzum🇧🇷 · J.-F. Paquet🇺🇸 · M. Singh🇺🇸 · J. Velkovska🇺🇸 · S. A. Bass🇺🇸 · C. Gale🇨🇦 · G. A. C. da Silva🇧🇷 · L. Du🇺🇸 · L. Kasper🇺🇸 · G. S. Rocha🇧🇷 and 44 other authors

    A comprehensive Bayesian analysis of the 3D dynamics of high-energy nuclear collisions is presented. We perform a systematic model-to-data comparison using simulations of large and small collision systems, and a broad range of measurements from the PHENIX, STAR, PHOBOS, and BRAHMS collaborations spanning nearly two decades of RHIC operations. In particular, we perform fully 3D multi-stage simulations including rapidity-dependent energy deposition with global energy conservation using the 3D Glauber model, along with relativistic viscous hydrodynamics with MUSIC. We calibrate the model on rapidity- and $p_T$-differential observables and analyze the respective constraints on initial state and transport properties they provide. We emphasize the additional constraints provided by rapidity-dependent measurements, the differences in large and small system calibrations, and the tension exhibited by particular observables. We use our calibrated model to make predictions of observables in p-Au and ${}^3$He-Au collisions. Furthermore, we facilitate direct comparison of experimental measurements by highlighting the dependence of flow measurements on the rapidity of the regions of interest and reference, as well as the importance of the centrality selection. In particular, we examine the apparent differences between the STAR and PHENIX $v_2$ and $v_3$ measurements in small systems.

    ↳ nucl-exhep-phnucl-thPRC(2026)·6 citations
36. 36*

    Quarkyonic matter with strangeness in an extended relativistic mean-field model

    Wei Sun🇨🇳 · Cheng-Jun Xia🇨🇳 · Ting-Ting Sun🇨🇳

    Quarkyonic matter is expected to play a key role for the transition from hadronic matter to quark matter in compact stars. Within the framework of the relativistic mean-field (RMF) model and equivparticle model with density-dependent quark masses, we construct the ``quark Fermi sea" with a ``baryon Fermi surface" to characterize the properties of the quarkyonic matter. In particular, we develop a comprehensive framework to account for the strangeness degrees of freedom, incorporating $\Lambda$, $\Xi$, and $\Sigma$ hyperons as well as strange quarks in a unified quarkyonic framework. Our calculations indicate that the inevitable emergence of hyperons softens the equations of state, leading to a reduction in the equilibrium sound velocity around $n_{\mathrm{b}}\approx 2n_0$, and consequently reducing the masses and radii of neutron stars. When the quark-hadron phase transition is taken into account, the equation of state at high densities exhibits additional softening consistent with current astronomical observational constraints. This softening leads to a maximum equilibrium sound velocity of $v_{eq}^{\max }\approx 0.6c$, which is close to the ultrarelativistic limit of $0.58c$.

    ↳ nucl-thhep-phPRD(2026)·1 citation
37. 37*

    Measurement of diboson production and precision EFT constraints in ATLAS

    Shu Li (on behalf of ATLAS Collaboration)🇨🇳

    These proceedings summarize the latest progress by the ATLAS Experiment at the LHC in measuring diboson production and related searches for physics beyond Standard Model via anomalous gauge couplings with the latest Effective Field Theory approach. The most recent measurements of $W^{+}{W}^{-}\to {\ell }^{+}\nu {\ell }^{-}\bar{\nu }$, $W^{\pm }Z\to 3\ell 1\nu$ and $Z(\to {\ell }^{+}{\ell }^{-})\gamma$ measurements with ATLAS full Run 2 dataset are presented, along with the highlights of the first evidence of $W^{+}{W}^{-}$ charge asymmetry, the first measurement of CP-violation sensitive observables in $WZ$, and, for the first time at the LHC, $SU(2{)}_L\otimes U(1{)}_Y$ fully gauge invariant anomalous neutral triple gauge coupling limits with $Z(\to {\ell }^{+}{\ell }^{-})\gamma$ process.

    ↳ hep-exhep-ph0 citations
38. 38*

    Geometric noise spectrum in interferometers

    Laurent Freidel🇨🇦 · Robin Oberfrank🇨🇦

    We study the power spectral density of time delay fluctuations in an interferometer as a potential low-energy quantum gravitational observable. We derive a general expression for the spectrum in terms of the Wightman function of linear metric perturbations, which we then apply to a variety of cases. We analyze the intrinsic graviton fluctuations in the vacuum, thermal, and squeezed states, as well as the fluctuations induced by the vacuum stress-energy of a massless scalar field. We find that the resulting spectra are free of ultraviolet divergences and that, while thermal and squeezed states provide a natural amplification mechanism, the spectra remain suppressed by the Planck scale.

    ↳ hep-thgr-qchep-ph6 citations
39. 39*

    Generation of gravitating solutions with Baryonic charge from Einstein-Scalar-Maxwell seeds

    Fabrizio Canfora🇨🇱 · Anibal Neira🇨🇱 · Seung Hun Oh🇰🇷

    We establish, for the first time, an exact correspondence between Einstein-scalar-Maxwell theory and gauged Skyrme-Maxwell-Einstein models in (3+1) dimensions. By constructing the simplest consistent ansatz within the gauged Skyrme-Maxwell framework, we reveal a remarkable equivalence in a sector that admits nonvanishing, highly magnetized baryonic charge. This correspondence has a particularly appealing consequence: it transfers the full power of solution-generating techniques developed for electrovacuum systems-many of which naturally accommodate scalar fields to the considerably more intricate setting of gauged Skyrme-Maxwell theory minimally coupled to General Relativity. As a result, it opens the door to a systematic and much broader exploration of exact solutions in Skyrme-Maxwell-Einstein theory and of their potential applications in cosmology and astrophysics. Notably, the resulting configurations carry nonzero baryonic charge whenever the derivative of the hadronic profile along the magnetic field lines does not vanish. As an illustrative example, we apply this new dictionary to a rotating Kerr-Newman-like spacetime dressed with a scalar field. In the corresponding Skyrme-Maxwell-Einstein solution, the quantization of the baryonic charge enforces a quantization of the Kerr rotation parameter. We derive an upper bound on the baryonic charge in terms of the integration constants of the solution and show that, in the regime of small baryonic charge, the rotation parameter depends linearly on the baryonic charge.

    ↳ gr-qchep-phhep-thEPJC(2026)·3 citations
40. 40*

    Hubble Tension as an Effect of Horizon Entanglement Nonequilibrium

    Alexander S. Sakharov🇺🇸 · Rostislav Konoplich🇺🇸 · Merab Gogberashvili🇬🇪 · Jack Simoni🇺🇸

    We propose an infrared mechanism for alleviating the Hubble constant tension, based on a small departure from entanglement equilibrium at the cosmological apparent horizon. If the horizon entanglement entropy falls slightly below the Bekenstein-Hawking value, we parametrize the shortfall by a fractional deficit $\delta (a)$ evolving with the FLRW scale factor $a$. The associated equipartition deficit at the Gibbons-Hawking temperature then sources a smooth, homogeneous component whose density scales as $H^2/G$, with a dimensionless coefficient $c_e^2(a)$ of order unity times $\delta (a)$. Because this component tracks $H^2$, it is negligible at early times but can activate at redshifts $z\lesssim 1$, raising the late time expansion rate by a few percent without affecting recombination or the sound horizon. We present a minimal three parameter activation model for $c_e^2(a)$ and derive its impact on the background expansion, effective equation of state, and linear growth for a smooth entanglement sector. The framework predicts a small boost in $H(z)$, a mild suppression of $f{\sigma }_8(z)$, and a corresponding modification of the low-$z$ distance-redshift relation. We test these predictions against current low-redshift data sets, including SN~Ia distance moduli, baryon acoustic oscillation distance measurements, cosmic chronometer $H(z)$ data, and redshift space distortion constraints, and discuss whether the $H_0$ tension can be consistently interpreted as a late-time, horizon-scale information deficit rather than an early universe modification.

    ↳ astro-ph.COgr-qchep-phhep-thUniverse(2026)·1 citation
41. 41*

    Vanishing Compactness Gap and Fermionic Compact Dark Matter in Hořava-Lifshitz Gravity

    Edwin J. Son🇰🇷 · Kyungmin Kim🇰🇷 · John J. Oh🇰🇷

    We show that the gap in the compactness between black holes and neutron stars witnessed in general relativity may be vanishing in Hořava-Lifshitz (HL) gravity. Assuming a fermion equation-of-state for simplicity, and solving the Tolman-Oppenheimer-Volkoff equation within the HL gravity framework, we see that there exists a minimum fermion mass $m_f^{\text{(min)}}(q,y)$, above which the gap of the compactness between black hole and fermionic compact object vanishes, for a given deformation parameter $q$ of HL and interaction strength $y$ between fermions. Thus, in HL gravity, the mass and radius of an object found in the lower mass gap by LIGO-Virgo-KAGRA observations might not be able to classify it as a black hole or a neutron star. It is interesting to note that a fermion of mass $\sim 40\text{GeV}$ can form a highly compact object of mass $\sim 10^{-4}\text{msun}$ and radius $\sim 1\text{m}$ that may play the role of the cold dark matter. In addition, we find the possible existence of another class of compact objects whose compactness is comparable to that of a black hole.

    ↳ gr-qchep-phhep-thPRD(2026)·1 citation
42. 42*

    EFT Perspective On de-Sitter S-Matrix

    Sayantan Choudhury🇮🇳

    Non-perturbative limitations on low-energy effective field theories (EFTs) based on the characteristics of high-energy theory are provided by the analyticity of the flat-space version of the S-matrix. Although the analyticity of the flat-space S-matrix is widely established, it is difficult to apply this framework to de Sitter space because the growing backdrop breaks time-translation symmetry and makes it more difficult to define asymptotic states. The flat-space analyticity imprint on the de Sitter S-matrix is examined in this study. On a certain limit, we derive a comprehensive relationship between the flat-space amplitude and the de Sitter S-matrix. In particular, we demonstrate that the relationship is valid for tree-level amplitude exchanging with arbitrary local derivative interactions with a large scalar field. Next, we contend that this specific limit is more consistent with the definition of EFT since, similar to flat space, the Mandelstam variable may be identified as the unique energy scale because the total energy dependence of the de Sitter S-matrix becomes negligible. Finally, we also find an unexpected connection between the idea of generalized energy conservation of an S-matrix of four-dimensional de Sitter and exceptional EFTs in de Sitter space. We restrict the coupling constants in theories of self-interacting scalars dwelling in the exceptional series of de Sitter representations by requiring that such an S-matrix only has support when the total energies of in and out states are equal. We rediscover the Dirac-Born-Infeld (DBI) and Special Galileon theories, in which a single coupling constant uniquely fixes the four-point scalar self-interactions.

    ↳ hep-thgr-qchep-ph1 citation
43. 43*

    The Regge-Gribov model with odderons

    M.A. Braun (Saint-Petersburg State University, Russia)🇷🇺 · E.M. Kuzminskii (Petersburg Nuclear Physics Institute, Russia)🇷🇺 · M.I. Vyazovsky (Saint-Petersburg State University, Russia)🇷🇺

    The Regge-Gribov model describing interacting pomerons and odderons is proposed with triple reggeon vertices taking into account the negative signature of the odderon. Its simplified version with zero transverse dimensions is first considered. No phase transition occurs in this case at the intercept crossing unity. This simplified model is studied without more approximations by numerical techniques. The physically relevant model in the two-dimensional transverse space is then studied by the renormalization group method in the single loop approximation. The pomeron and odderon are taken to have different bare intercepts and slopes. The behaviour when the intercepts move from below to their critical values compatible with the Froissart limitation is studied. Five real fixed points are found with singularities in the form of non-trivial branch points indicating a phase transition as the intercepts cross unity. The new phases, however, are not physical, since they violate the projectile-target symmetry. In the vicinity of fixed points the asymptotical behaviour of Green functions and elastic scattering amplitude is found under Glauber approximation for couplings to participants.

    ↳ hep-thhep-phTheor.Math.Phys.(2026)·1 citation
44. 44*

    Lattice determination of the neutrino background for $J/\psi \to \gamma +\text{invisible}$

    Yu Meng🇨🇳 · Ning Li🇨🇳 · Chuan Liu🇨🇳 · Haobo Yan🇨🇳 · Ke-Long Zhang🇨🇳 · Xue-Ze Zhang🇨🇳

    Searching for dark matter is a primary goal of modern astronomy and particle physics. Invisible decays of heavy quarkonia are particularly promising for probing light dark matter, attracting broad interest due to their unique sensitivity. Experiments searching for radiative invisible decays of the $J/\psi$ have steadily improved upper limits, and upcoming facilities will push sensitivity further--making the precise determination and subtraction of the neutrino background indispensable. Here, we present the first lattice QCD calculation of the Standard Model decay $J/\psi \to \gamma \nu \bar{\nu }$, an irreducible background to $J/\psi \to \gamma +\text{invisible}$. Our result for the branching fraction is $\mathrm{Br}(J/\psi \to \gamma \nu \bar{\nu })=1.04(7)(8)\times 10^{-10}$, where the first uncertainty is statistical and the second is our systematic estimate. This work advances lattice-based determinations of neutrino backgrounds to quarkonium invisible decays, delivering an ab initio benchmark for $J/\psi \to \gamma +\text{invisible}$. Our approach generalizes to other quarkonium channels (e.g., ${\rm Y}/\varphi \to \gamma +\text{invisible}$) and provides critical theoretical support for dark matter searches at colliders.

    ↳ hep-lathep-exhep-phPRD(2026)·1 citation
45. 45*

    Hamiltonian formulation of the $1+1$-dimensional ${\varphi }^4$ theory in a momentum-space Daubechies wavelet basis

    Mrinmoy Basak🇮🇳 · Debsubhra Chakraborty🇮🇳 · Nilmani Mathur🇮🇳 · Raghunath Ratabole🇮🇳

    We apply the wavelet formalism of quantum field theory to investigate nonperturbative dynamics within the Hamiltonian framework. In particular, we employ Daubechies wavelets in momentum space, whose basis functions are labeled by resolution and translation indices, providing a natural nonperturbative truncation of both infrared and ultraviolet truncation of quantum field theories. As an application, we compute the energy spectra of a free scalar field theory and the interacting $1+1$-dimensional ${\varphi }^4$ theory. This approach successfully reproduces the well-known strong-coupling phase transition in the $m^2>0$ regime. We find that the extracted critical coupling systematically converges toward its established value as the momentum resolution is increased, demonstrating the effectiveness of the wavelet-based Hamiltonian formulation for nonperturbative field-theoretic calculations.

    ↳ hep-thhep-exhep-lathep-ph+1PRD(2026)·2 citations
46. 46*

    The phase structure of QCD: Fluctuations and Correlations

    Peter Braun-Munzinger🇩🇪 · Anar Rustamov🇩🇪 · Nu Xu🇨🇳

    The strong interaction - governed by Quantum Chromodynamics (QCD) - shapes the structure of the visible universe. At about 10 $\mu$s after the big bang, the primordial matter made up of quarks and gluons plus leptons, photons and neutrinos, the quark-gluon plasma (QGP), became cool enough to create, in a phase transition, the protons and neutrons of ordinary matter, along with other strongly interacting unstable hadrons. This phase transition was predicted within the framework of QCD and has been studied in accelerator laboratories world-wide since about 40 years. This review will explore recent breakthroughs in the study of the QCD phase diagram. We will highlight measurements of particle production and fluctuations, and compare them to theoretical predictions. We summarize our current understanding of the QCD structure and outline future experimental opportunities with high energy nuclear collisions at fixed-target and collider facilities world-wide.

    ↳ nucl-exhep-ph7 citations
47. 47*

    Ultra-fast growth of primordial black holes through radiative absorption

    Dimitris S. Kallifatides🇬🇷 · Theodoros Papanikolaou🇮🇹 · Emmanuel N. Saridakis🇬🇷

    We show that Schwarzschild primordial black holes (PBHs) formed in the radiation-dominated era can grow extremely rapidly through $\text{radiative absorption}$ governed by the full Stefan-Boltzmann law. By introducing a principle of isonomy - ensuring identical particle species dependence for Hawking emission and absorption - we find that, whenever the temperature of the PBH environment is larger than the PBH horizon temperature, PBHs generically gain mass. In particular, for PBH masses following the critical collapse mass-scaling law with critical exponent ${\gamma }_{\mathrm{crit}}$, with ${\gamma }_{\mathrm{crit}}\in (0.33,0.49)$, the aforementioned radiative absorption mass growth mechanism produces a striking effect: PBHs forming with a mass $10^6{M}_{\odot }$ during BBN can reach $\mathcal{O}(10^{10}{M}_{\odot })$ within $\mathcal{O}(10^6\mathrm{s})$ ($\sim$ 58 days). Interestingly enough, small deviations from ${\gamma }_{\mathrm{crit}}$, depending itself on the number of relativistic species present in the primordial plasma, yield a continuous PBH mass spectrum providing us ultimately with a single, Standard-Model-based explanation for the origin of stellar-mass, intermediate-mass, and supermassive black holes (SMBHs), and naturally accounting for the early appearance of SMBHs. The Schwarzschild treatment presented here can be extended to spherically symmetric cosmological black holes, indicating that radiative absorption is a dominant and previously overlooked PBH growth channel in the early Universe.

    ↳ astro-ph.COgr-qchep-ph7 citations
48. 48*

    Role of the symmetry energy on hybrid stars

    H. Güven🇫🇷 · K. Bozkurt🇹🇷 · E. Khan🇫🇷 · J. Margueron🇺🇸

    The impact of the symmetry energy on the properties of compact stars is analyzed considering constraints from nuclear physics and astrophysics. A compact star can be a neutron star composed only of nuclear matter or a hybrid star with a quark core. Two typical models (soft and stiff) are considered for the nuclear equation of state, and for the hybrid one, a parameterized first-order phase transition approach, completed with a linear quark matter equation of state, is implemented. We show that the phase transition reduces the tension between GW170817 and NICER observations, and we illustrate the impact of the symmetry energy for the understanding of the nature of the binary system in GW170817. We also confirm our previous findings that the GW170817 waveform is best described as a binary HS with a low-density onset of stiff quark matter. This could also be interpreted as a quarkyonic cross-over.

    ↳ nucl-thastro-ph.HEastro-ph.SRhep-ph1 citation
49. 49*

    Thermal Gauge Theory for a Rotating Plasma

    Alberto Salvio🇮🇹

    This paper provides a systematic and complete study of thermal gauge theory for generic equilibrium density matrices, which feature arbitrary values not only of temperature and chemical potentials, but also of average angular momentum. This work extends previous studies, which focused on pure scalar-fermion theories, to all gauge theories coupled to an arbitrary matter sector. Path-integral methods are developed to study ensemble averages and thermal Green's functions of general operators, with an arbitrary number of points, in all interacting gauge theories. These methods cover both the real-time and imaginary-time formalisms. Generalized Kubo-Martin-Schwinger (KMS) conditions are obtained both in coordinate and in momentum space for operators in general representations of the Lorentz and internal symmetry group. This allows us to obtain all thermal propagators including those of gauge fields and Faddeev-Popov ghosts. By analyzing all interactions in detail, it is shown that, in perturbation theory, only the propagators are affected by the average angular momentum and the chemical potentials, the vertices remain unmodified. The paper presents fully model-independent results and can, therefore, be applied to any specific thermal field theory.

    ↳ hep-thhep-ph4 citations
50. 50*

    "Observations on the possible electromagnetic nature of nucleon interactions and pions" -- historical manuscript from 1969 by B. W. Ninham and C. Pask

    Mathias Boström🇵🇱 · Drew F. Parsons🇮🇹

    This manuscript presents an historical perspective prepared by Barry Ninham and Colin Pask in 1969 on the connection between quantum electrodynamics theory and nucleon interactions. A new theory of strong interactions based on electromagnetic considerations is proposed. Energy and force range magnitudes are correctly given. A new theory of the pion emerges and the pion mass and lifetime are calculated. No strong interaction coupling constant is required.

    ↳ nucl-thcond-mat.mtrl-scihep-phphysics.hist-phSubstantia, 2025·1 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.