Mon·Oct 13, 2025Monday·October 13, 2025

1. 01*

   Loop functions of sunset diagrams in 2+1 space-time dimensions

   N. Kaiser🇩🇪

   In these notes the relativistic $n$-body phase-phase is calculated iteratively in $2+1$ space-time dimensions for all $n$. The obtained result shows a simple power-law behavior ${\alpha }_n(\mu -M{)}^{n-2}/\mu$ with a dependence only on the total mass $M=m_1+\cdots +m_n$. As a consequence of this feature, the $(n-1)$-loop integrals $J_n(-q^2)$ associated to sunset diagrams with $n$ internal lines can be expressed through of elementary (arctangent and logarithmic) functions, modulo polynomial terms in $q^2$ with regularization-dependent coefficients. An outlook to the analogous situation in $4+1$ space-time dimensions is given by computing the $n$-body phase-phases for $n=2,3,4,5$ with their totally symmetric dependence on the involved masses. Moreover, a digression to $1+1$ space-time dimensions reveals that there the three-body phase-space is already proportional to a complete elliptic integral.

   hep-ph0 citations
2. 02*

   Taming forward scattering singularities in partial waves

   Marta Fuentes Zamoro🇪🇸 · Benjamín Grinstein🇺🇸 · Pablo Quílez🇺🇸

   Perturbative partial-wave amplitudes diverge in cases with a massless exchanged particle in the $t$-channel. We argue that the divergence is an artifact of perturbation theory and give a prescription for the all-orders correction factor that renders the partial waves finite. As an example, we apply this to longitudinal $W^{+}{W}^{-}$ elastic scattering, for which there is a photon exchange $t$-channel contribution, and derive improved quasi-perturbative unitarity bounds on the mass of the Higgs. The method is also useful for $t$-channel exchange of very light particles.

   hep-phhep-th5 citations
3. 03*

   Exclusive photoproduction of light and heavy vector mesons: thresholds to very high energies

   Lin Tang🇨🇳 · Hui-Yu Xing🇨🇳 · Minghui Ding🇨🇳 · Craig D. Roberts🇨🇳

   A reaction model for $\gamma +p\to V+p$, $V={\rho }^0,\varphi ,J/\psi ,{\rm Y}$, which exposes the quark-antiquark content of the photon in making the transition $\gamma \to q\bar{q}+\mathbb{P}\to V$, where $q$ depends on $V$, and couples the intermediate $q\bar{q}$ system to the proton's valence quarks via Pomeron ($\mathbb{P}$) exchange, is used to deliver a unified description of available data -- both differential and total cross sections -- from near threshold to very high energies, $W$, for all the $V$-mesons. For the ${\rm Y}$, this means $10\lesssim W/\mathrm{GeV}\lesssim 2000$. Also provided are predictions for the power-law exponents that are empirically used to characterise the large-$W$ behaviour of the total cross sections and slope parameters characterising the near-threshold differential cross sections. Appealing to notions of vector meson dominance, the latter have been interpreted as vector-meson--proton scattering lengths. The body of results indicate that it is premature to link any $\gamma +p\to V+p$ data with, for instance, in-proton gluon distributions, the quantum chromodynamics trace anomaly, or pentaquark production. Further developments in reaction theory and higher precision data are required before the validity of any such links can be assessed.

   hep-phhep-exhep-latnucl-ex+1EPJC(2026)·11 citations
4. 04*

   Towards Quantum Simulations of Sphaleron Dynamics at Colliders

   Min Huang🇨🇳 · Ying-Ying Li🇨🇳 · Yandong Liu🇨🇳 · Hao Zhang🇨🇳

   Sphaleron dynamics in the Standard Model at high-energy particle collisions remains experimentally unobserved, with theoretical predictions hindered by its nonperturbative real-time nature. In this work, we investigate a quantum simulation approach to this challenge. Taking the $1+1$D $O(3)$ model as a protocol towards studying dynamics of sphaleron in the electroweak theory, we identify the sphaleron configuration and establish lattice parameters that reproduce continuum sphaleron energies with controlled precision. We then develop quantum algorithms to simulate sphaleron evolutions where quantum effects can be included. This work lays the ground to establish quantum simulations for studying the interaction between classical topological objects and particles in the quantum field theory that are usually inaccessible to classical methods and computations.

   hep-phhep-exhep-lathep-thPRD(2026)·3 citations
5. 05*

   Open heavy-flavor transport and hadronization in heavy-ion collisions

   Yu Fu🇺🇸 · Tharun Krishna🇺🇸 · Weiyao Ke🇨🇳 · Steffen A. Bass🇺🇸 · Ralf Rapp🇺🇸

   We develop a comprehensive model for heavy-quark evolution in a realistic QGP, from their production in the initial collision to hadronic freeze-out. Heavy-quark transport is described by a Langevin approach including medium-induced radiation, coupled to a 2+1D viscous hydrodynamic bulk evolution. Transport coefficients are obtained from non-perturbative $T$-matrix calculations with resonant correlations near the transition temperature. Hadronization is implemented via two fragmentation+recombination schemes: an improved sudden coalescence model and a resonance recombination model. We present results for key open heavy-flavor observables, i.e., the nuclear modification factor and elliptic flow, and compare to LHC Pb-Pb data at $\sqrt{s_{\text{NN}}}$=5.02\,TeV.}

   hep-phEPJ Web Conf.(2026)·1 citation
6. 06*

   Jet Energy-Energy Correlator in Cold QCD Matter

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

   We present a study of medium-induced modifications to the energy-energy correlator (EEC) for jets in cold nuclear matter. For electron-nucleus collisions, at leading order in the QCD coupling and in the jet-medium interaction, we derive an analytic expression for the EEC modification as a function of the opening angle and show that the modification is strongest at large angles within the jet cone. The dependence on jet energy, the transport properties of cold nuclear matter, and the in-medium path length is made explicit. We further extend the analysis to gluon jets in proton-nucleus collisions and compare with preliminary proton-lead data from the LHC. Possible effects of comovers on the EEC in proton-nucleus collisions are also discussed.

   hep-phEPJ Web Conf.(2026)·0 citations
7. 07*

   Semihard interactions at TeV energies

   T. V. Iser🇧🇷 · E. G. S. Luna🇧🇷

   We investigate the high-energy behavior of the total cross section, ${\sigma }_{\text{tot}}$, and the ratio of the real to imaginary parts of the scattering amplitude, $\rho$, in both proton-proton and antiproton-proton channels. Our analysis is based on a QCD-inspired model in which the rise of the cross sections is predominantly driven by semihard processes involving gluons. We address the tension between measurements from the ATLAS/ALFA and TOTEM Collaborations, showing that independent analyses of their datasets can provide statistically consistent descriptions of the overall data, even though they do not fully reproduce the central values of the $\rho$ parameter at $\sqrt{s}=13$ TeV. The slight discrepancy between these central values and the model's predicted values, obtained using an asymptotic dominant crossing-even elastic scattering amplitude, points to the potential presence of an odd component in the semihard amplitude at high energies.

   hep-phhep-exnucl-thPRD(2025)·0 citations
8. 08*

   When inverse seesaw meets inverse electroweak phase transition: a novel path to leptogenesis

   Wen-Yuan Ai🇦🇹 · Peisi Huang🇺🇸 · Ke-Pan Xie🇨🇳

   We propose a new nonthermal leptogenesis mechanism triggered by the cosmic first-order phase transition. The Standard Model is extended with two generations of TeV-scale vectorlike leptons. The lighter generation gives rise to an inverse electroweak phase transition of the Higgs field at $T\sim 200\mathrm{GeV}$, restoring the symmetry, and resulting in relativistic bubble expansion in the space. The heavier generation is responsible for neutrino masses via the inverse seesaw mechanism. The interaction between bubble walls and particles in the plasma abundantly produces the vectorlike leptons, and they subsequently undergo CP-violating decay to generate the baryon asymmetry. This mechanism is testable at current and future particle experiments.

   hep-phastro-ph.COJHEP(2026)·8 citations
9. 09*

   Inclusive processes in the modified Quark-Gluon String Model

   M.N. Sergeenko🇧🇾

   Inclusive processes at high energies are studied in a non-perturbative approach in QCD using a modified Quark-Gluon String Model. Theoretical and experimental aspects of diffraction dissociation are discussed. In the calculations of cross sections, the parameters of complex nonlinear trajectories of Pomeranchuk and Reggeons are used. Particular attention is paid to elastic and inelastic processes at LHC energies.

   hep-phPhys.Part.Nucl.(2025)·0 citations
10. 10*

    HOPPET v2 release note

    Alexander Karlberg🇨🇭 · Paolo Nason🇮🇹 · Gavin Salam🇬🇧 · Giulia Zanderighi🇩🇪 · Frédéric Dreyer🇺🇸

    We document the three main new features in the v2 release series of the HOPPET parton distribution function evolution code, specifically support for N${}^3$LO QCD evolution in the variable flavour number scheme, for the determination of hadronic structure functions for massless quarks up to N${}^3$LO, and for QED evolution to an accuracy phenomenologically equivalent to NNLO QCD. Additionally we describe a new Python interface, CMake build option, functionality to save a hoppet table as an LHAPDF grid and update our performance benchmarks, including optimisations in interpolating PDF tables.

    hep-phEPJC(2026)·16 citations
11. 11*

    MSHT Approximate N3LO PDFs: Updates and Consequences for Phenomenology

    T. Cridge🇧🇪 · L. A. Harland-Lang🇬🇧 · R. S. Thorne🇬🇧

    We present updates to the MSHT approximate N3LO PDFs focusing upon recent developments, examining the impacts of newly determined splitting function and transition matrix element calculations, performed since the public MSHT20aN3LO PDF set was released. We observe only small changes to the output PDFs, at most of similar size to their quoted uncertainties and typically notably less. Finally, we also present the impacts on the PDF luminosities, where changes are generally further reduced.

    hep-phPoS(2025)·6 citations
12. 12*

    Dark matter production from evaporation of regular primordial black holes

    Ngo Phuc Duc Loc🇺🇸

    We point out that a simple redefinition of the regularizing parameter in regular black hole (RBH) metrics can preserve the self-similarity of the evaporation process. This implies that a RBH can evaporate completely, mirroring the behavior of its singular counterpart. Consequently, RBHs need not evolve into exotic, unverified remnant states such as horizonless compact objects or wormholes. We then provide a general framework to study dark matter (DM) production from evaporation of regular primordial black holes (RPBHs). As illustrative examples, we explicitly work out the cases of the Hayward metric and the Simpson-Visser metric. The formalism can be readily applied to other metrics. RPBH generally exhibits different Hawking temperature and horizon size compared to their singular counterpart, leading to distinct lifetime and mass evolution. We calculate the resulting modified cosmological constraints and the allowed parameter space to obtain the correct DM abundance. This intriguing scenario provides a unified resolution to both the DM problem and the black hole singularity problem, while preserving the standard self-similar evaporation process.

    hep-phgr-qchep-thEPJC(2026)·6 citations
13. 13*

    The two-mass contributions to the three-loop massive operator matrix elements ${\tilde{A}}_{Qg}^{(3)}$ and $\Delta {\tilde{A}}_{Qg}^{(3)}$

    J. Ablinger🇦🇹 · J. Blümlein🇩🇪 · A. De Freitas🇦🇹 · A. von Manteuffel🇩🇪 · C. Schneider🇦🇹 · K. Schönwald🇨🇭

    We calculate the two-mass three-loop contributions to the unpolarized and polarized massive operator matrix elements ${\tilde{A}}_{Qg}^{(3)}$ and $\Delta {\tilde{A}}_{Qg}^{(3)}$ in $x$-space for a general mass ratio by using a semi-analytic approach. We also compute Mellin moments up to $N=2000(3000)$ by an independent method, to which we compare the results in $x$-space. In the polarized case, we work in the Larin scheme. We present numerical results. The two-mass contributions amount to about $50\%$ of the full \textcolor{blue}{$O(T_F^2)$} and \textcolor{blue}{$O(T_F^3)$} terms contributing to the operator matrix elements. The present result completes the calculation of all unpolarized and polarized massive three-loop operator matrix elements.

    hep-phhep-thJHEP(2026)·9 citations
14. 14*

    Manifestations of Dark Matter in processes with three and four Top-Quarks

    E. Abasov🇷🇺 · E. Boos🇷🇺 · V. Bunichev🇷🇺 · P. Volkov🇷🇺 · G. Vorotnikov🇷🇺 · L. Dudko🇷🇺 · A. Zaborenko🇷🇺 · E. Iudin🇷🇺 · A. Markina🇷🇺 · M. Perfilov🇷🇺 · N. Savkova🇷🇺

    This study explores possible manifestations of Dark Matter (DM) in processes involving multiple top quarks at the LHC. We analyze both the associated production of scalar and pseudoscalar DM Mediators with up to four top quarks, as well as their resonant production in top-rich final states, within a simplified model framework. Cross sections were calculated using the CompHEP and MadGraph packages with benchmark parameters recommended by the LHC Dark Matter Working Group. A detailed comparison of differential cross sections for key kinematic observables in three- and four-top-quark production demonstrates pronounced deviations from Standard Model predictions. The results highlight the limited feasibility of associated production channels, while resonant DM Mediator production offers realistic discovery prospects. Overall, the analysis underscores the potential of multi-top-quark final states as sensitive probes of Dark Matter at current and future collider experiments.

    hep-phMoscow Univ.Phys.Bull.(2025)·0 citations
15. 15*

    Lie symmetry analysis of the two-Higgs-doublet model field equations

    M. Aa. Solberg🇳🇴

    We apply Lie symmetry analysis of partial differential equations (PDEs) to the Euler-Lagrange equations of the two-Higgs-doublet model (2HDM), to determine its scalar Lie point symmetries. A Lie point symmetry is a structure-preserving transformation of the spacetime variables and the fields of the model, which is also continuous and connected to the identity. Symmetries of PDEs may, in general, be divided into strict variational, divergence and non-variational symmetries, where the first two are collectively referred to as variational symmetries. Variational symmetries are usually preserved under quantization, and variational Lie symmetries yield conservation laws. We demonstrate that there are no scalar Lie point divergence symmetries or non-variational Lie point symmetries in the 2HDM, and re-derive its well-known strict variational Lie point symmetries, thus confirming the consistency of our implementation of Lie's method. Moreover, we prove three general results that may simplify Lie symmetry calculations for a wide class of particle physics models. Lie symmetry analysis of PDEs is broadly applicable for determining Lie symmetries. As demonstrated in this work, the method can be applied to models with many variables, parameters, and reparametrization freedom, while any missing discrete symmetries can be identified through the automorphism groups of the resulting Lie symmetry algebras.

    hep-phhep-thmath-phmath.MPPhys.Scripta(2026)·3 citations
16. 16*

    A LENS on DUNE-PRISM: Characterizing a Neutrino Beam with Off-Axis Measurements

    Julia Gehrlein🇺🇸 · Joachim Kopp🇨🇭 · Margot MacMahon🇬🇧 · George A. Parker🇩🇪

    Upcoming precision long-baseline neutrino oscillation experiments will be severely limited by the large systematic uncertainties associated with neutrino flux predictions and neutrino--nucleus cross sections. A promising remedy is the PRISM (Precision Reaction Independent Spectrum Measurement) technique, whereby the near detector measures the neutrino spectrum at different angles with respect to the beam axis. These measurements are then linearly combined into a prediction of the oscillated neutrino flux at the far detector. This prediction is data-driven, but still dependent on some theoretical knowledge about the neutrino flux. In this paper, we study to what extent off-axis measurements themselves can be used to directly constrain neutrino flux models. In particular, we use them to extract separately the fluxes and spectra of different meson species in the beam. We call this measurement LENS (Lateral Extraction of Neutrino Spectra). Second, we demonstrate how the thus improved flux model helps to further constrain the far detector flux prediction, thereby ultimately improving oscillation measurements.

    hep-phhep-ex4 citations
17. 17*

    Observation of a pseudoscalar excess at the $t\bar{t}$ threshold

    Alexander Grohsjean🇨🇭

    The CMS Collaboration recently observed a pseudoscalar excess of top quark-antiquark ($t\bar{t}$) events near the production threshold. One possible interpretation involves the formation of a short-lived quasi-bound state of $t\bar{t}$. This proceeding summarizes the first presentation of the results at the 59th Rencontres de Moriond and outlines its potential implications.

    ↳ hep-exhep-ph0 citations
18. 18*

    Experimental overview: quarkonia as probes for deconfinement

    Michael Winn🇫🇷

    The current status of the experimental investigation of quarkonia in heavy-ion collisions as probes for deconfinement is reviewed. The emphasis is put on the qualitative understanding of charmonia (ccbar bound states) and bottomonia (bbbar) based on the results in the past few years. In particular, the observation of non-primordial J/psi (ccbar) production as signature of deconfinement based on different observables and the sequential suppression patterns of the Upsilon (bbbar) states are discussed. An outlook focusing on the time scale until the next quark matter conference is provided.

    ↳ nucl-exhep-exhep-phEPJ Web Conf.(2026)·0 citations
19. 19*

    Thermal and Magnetic effects on Bulk Viscosity in Binary Neutron Star Mergers

    Pranjal Tambe🇮🇳 · Debarati Chatterjee🇮🇳 · Mark Alford🇺🇸 · Alexander Haber🇬🇧

    Astrophysical scenarios such as binary neutron star mergers, protoneutron stars, and core-collapse supernovae involve finite temperatures and strong magnetic fields. Previous studies on the effect of magnetic fields on flavor-equilibration processes relied on the Fermi surface approximation, which is not a reliable approximation in the neutrino-transparent regime of matter in supernovae or neutron star mergers. In a recent study, we went beyond the Fermi surface approximation, performing the full phase space integral to obtain direct Urca rates in a background magnetic field. In this work, we extend these calculations to incorporate the collisional broadening (modified Urca) contribution. We use the recently developed nucleon width approximation, which naturally includes the magnetic field dependence of all contributions. We demonstrate the impact of magnetic fields on the flavor-equilibrium condition for two finite-temperature equations of state with different direct Urca thresholds. We also study the impact of magnetic fields on the bulk viscous dissipation of density oscillations relevant in postmerger scenarios.

    ↳ nucl-thastro-ph.HEhep-phPRC(2026)·2 citations
20. 20*

    Emergence of the $\pi (1300)$ Resonance from Lattice QCD

    Haobo Yan🇨🇳 · Maxim Mai🇺🇸 · Marco Garofalo🇩🇪 · Yuchuan Feng🇺🇸 · Michael Döring🇺🇸 · Chuan Liu🇨🇳 · Liuming Liu🇨🇳 · Ulf-G. Meißner🇩🇪 · Carsten Urbach🇩🇪

    The mass of the lightest hadron in nature, the pion, is one seventh of that of the nucleon and one tenth of the mass of its first excited state, the $\pi (1300)$. This enormous energy difference opens an interesting window into the confinement of quarks and the structure of the lightest hadrons. In this Letter, we provide the first calculation of resonance parameters of the $\pi (1300)$ from lattice quantum chromodynamics (QCD). For this purpose, recently derived state-of-the-art tools are adapted and applied both in the construction of three-hadron operators and for mapping finite-volume spectra to infinite-volume amplitudes, subsequently analytically continuing these to complex energies. For our heavy pion mass ensembles, we find a clear signal of the resonance. Making a simple assumption of vanishing pion mass dependence for the three-body force, but incorporating constraints from Chiral Perturbation Theory for all the two-body channels, enables a robust extrapolation to the physical point. Applying model averaging, we extract a pole position of $M_{\pi (1300)}=(1169\pm 46)-i(62_{-62}^{+168})\text{MeV}$ supporting values from phenomenology.

    ↳ hep-lathep-phnucl-thPRL(2026)·21 citations
21. 21*

    Yukawa interactions in Quantum Gravity

    Gustavo P. de Brito🇧🇷 · Manuel Reichert🇬🇧 · Marc Schiffer🇨🇦

    We present the first complete next-to-leading-order analysis of a Yukawa system within the framework of asymptotically safe quantum gravity. Our results are obtained through a systematic resummation of higher-order operators, revealing two distinct resummation mechanisms -- one of which has not been explored previously. In addition, we introduce a novel approach to estimate systematic uncertainties by simulating the impact of neglected higher-order contributions. We demonstrate that quantum gravity fluctuations anti-screen Yukawa interactions, thereby resolving previously inconclusive leading-order results. This anti-screening mechanism enables the generation of finite interactions from an asymptotically free Yukawa fixed point. Consequently, our findings provide strong evidence that non-vanishing Yukawa couplings are compatible with asymptotically safe quantum gravity, which is a necessary requirement for the Standard Model to emerge from an asymptotically safe ultraviolet completion.

    ↳ hep-thgr-qchep-ph9 citations
22. 22*

    The Effective Radius of an Electric Point Charge in Nonlinear Electrodynamics

    Tengyang Liu🇨🇳 · Yisong Yang🇺🇸

    Motivated by the century-old problem of modeling the electron as a pointlike particle with finite self energy, we develop a new class of nonlinear perturbations of Maxwell's electrodynamics inspired by, but distinct from, the Born--Infeld theory. A hallmark of our construction is that the effective radius of an electric point charge can be reduced arbitrarily by tuning a coupling parameter, thereby achieving scales far below the Born--Infeld bound and consistent with the experimentally undetected size of the electron. The models preserve finite self energy for point charges while energetically excluding monopoles and dyons, a robustness that appears intrinsic to this class of nonlinear theories. Two complementary behaviors are uncovered: In the non-polynomial perturbations, the Maxwell limit is not recovered as the coupling vanishes, whereas in polynomial models the self energy diverges correctly, meaning that the Maxwellian ultraviolet structure is reinstated. A further subtlety emerges in the distinction between the prescribed source charge, imposed through the displacement field, and the measurable free charge arising from the induced electric field. In particular, the free charge and the self energy contained within any ball around the point charge tend to zero in the strong-nonlinearity or zero effective-radius limit, rendering a pointlike structure locally undetectable, both electrically and energetically. These findings highlight how nonlinear field equations reconcile theoretical prescription with experimental measurement and suggest a classical rationale for the effective invisibility of the electron substructure.

    ↳ physics.class-phhep-phhep-thmath-ph+11 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.