Tue·Oct 7, 2025Tuesday·October 7, 2025

1. 01*

   Effects of hadronic molecule $N(2080)3/2^{-}$ on $K^{\ast +}\Lambda$ photoproduction

   Wen-Ya Tian🇨🇳 · Neng-Chang Wei🇨🇳 · Yu-Fei Wang🇨🇳 · Fei Huang🇨🇳 · Bing-Song Zou🇨🇳

   In our previous work [Phys. Rev. C {\bf 101}, 014003 (2020)], we have analyzed all available data on differential cross sections and spin density matrix elements for the $\gamma p\to K^{\ast +}\Lambda$ reaction using an effective Lagrangian approach. There, the $t$-channel $K$, $K^{\ast }$, and $\kappa$ exchanges, the $u$-channel $\Lambda$, $\Sigma$, and ${\Sigma }^{\ast }$ exchanges, the $s$-channel $N$, $N(2060)5/2^{-}$, and $N(2000)5/2^{+}$ exchanges, and the interaction current were taken into account in constructing the reaction amplitudes. It was found that, overall, the agreement of the theoretical results with the corresponding data is fairly good. However, noticeable discrepancies between the model results and the data on spin density matrix elements ${\rho }_{00}$ are still observed in the center-of-mass energy region around $W\approx 2.08$ GeV, indicating the need for additional reaction mechanisms. On the other hand, the hidden-strange pentaquark-like state $N(2080)3/2^{-}$, which is proposed to be a $K^{\ast }\Sigma$ molecular state as the strange partner of $P_c(4457)$ hadronic molecule, has been found to play quite active roles in reproducing the data for $K^{\ast +}{\Sigma }^0$, $K^{\ast 0}{\Sigma }^{+}$, and $\varphi p$ photoproduction reactions. Based on these observations, in the present work, we reanalyze the data for the $\gamma p\to K^{\ast +}\Lambda$ reaction by incorporating the pentaquark-like state $N(2080)3/2^{-}$ in our previously proposed model. The results show that with the inclusion of the contributions of $N(2080)3/2^{-}$, the quality of the theoretical description of the $\gamma p\to K^{\ast +}\Lambda$ data can be considerably improved.

   hep-phnucl-thPRC(2025)·4 citations
2. 02*

   Spectroscopy and Radiative Decays of ${\Omega }_{ccc}$ and ${\Omega }_{bbb}$ Baryons in a Quark-Diquark Model

   Chaitanya Anil Bokade🇮🇳 · Bhaghyesh

   We present a comprehensive study of the spectra and radiative decays of the triply heavy baryons ${\Omega }_{ccc}$ and ${\Omega }_{bbb}$ within a quark-diquark framework using a screened potential model. The analysis is carried out by solving a relativized Hamiltonian for a two-body bound system: the diquark masses are first determined, after which each baryon is treated as a composite of the diquark and the third quark. Employing the obtained wave functions, we calculate electromagnetic transitions using the $E1$ and $M1$ operators. We report mass spectra together with $E1/M1$ decay widths for radially and orbitally excited states, and systematically compare our results with those from other theoretical approaches.

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

   Searching for New Physics with the Large Hadron Collider

   Michael Spannowsky🇬🇧

   This chapter provides an introduction to collider phenomenology, explaining how theoretical concepts are translated into experimental analyses at the Large Hadron Collider (LHC). Beginning with the principles of collider operation and detector design, it outlines how collisions of protons are modelled through parton distribution functions, hard matrix elements, parton showers, and hadronisation. The discussion then turns to the reconstruction of physical objects and the definition of kinematic observables that expose the quantum numbers and dynamics of the underlying interactions. Special emphasis is placed on jet physics, including infrared- and collinear-safe algorithms, grooming and tagging techniques, and modern reconstruction approaches to jet substructure. The chapter introduces event selection strategies, object identification, and multivariate classification methods, before presenting the statistical framework underpinning modern collider analyses, from likelihood construction to hypothesis testing and uncertainty treatment. Three representative case studies, the Higgs discovery in the diphoton channel, high-mass dilepton resonance searches, and constraints on new physics through the Standard Model Effective Field Theory, demonstrate how these ingredients combine in end-to-end analyses. The chapter concludes with a perspective on future colliders and the growing role of open data and simplified likelihoods in enabling reinterpretation and global fits.

   hep-ph2 citations
4. 04*

   Angular observables and branching ratio for $B_s\to \varphi {\ell }^{+}{\ell }^{-}$ decay

   Aidos Issadykov🇷🇺

   In this paper, an analysis of the $B_s\to \varphi {\ell }^{+}{\ell }^{-}$ rare decay is presented within the framework of the covariant confined quark model. The $B_s\to \varphi$ transition form factors are calculated and then used to compute the branching fractions and angular observables in various $q^2$ bins, including the forward-backward asymmetry $A_{FB}$, the longitudinal polarization $F_L$, and the optimized observables $A_i$ and $S_i$. The results show agreement with the latest experimental data given by LHCb collaboration and compared with available theoretical predictions.

   hep-phhep-exPTEP(2026)·0 citations
5. 05*

   A reassessment of the role of high $x$ data on the MSHT global PDF fit

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

   We present updates within the MSHT global PDF fit that focus on the high $x$ region, and on improving our understanding of the interplay of various theoretical contributions and experimental constraints here. We revisit the question of target mass and higher twist corrections, considering their impact for the first time at approximate N${}^3$LO order in a global PDF analysis. Their inclusion is found to be moderate but not negligible on both the PDFs and preferred value of the strong coupling. Increased stability in these at aN${}^3$LO is observed in comparison to lower orders. We also study the impact of an updated treatment of various fixed-target DIS data, the inclusion of Seaquest fixed-target Drell Yan data, and new ZEUS data that extends coverage into the high $x$ region. The Seaquest data have the largest effect of these, in particular on the light quark separation at high $x$, while the impact of the other updates is rather mild.

   hep-phEPJC(2026)·10 citations
6. 06*

   Systematic analysis of the transition form factors of $B_c$ to $D$-wave charmonia and corresponding semileptonic decays

   Jie Lu🇨🇳 · Dian-Yong Chen🇨🇳 · Guo-Liang Yu🇨🇳 · Zhi-Gang Wang🇨🇳

   In this article, the vector, axial vector and tensor form factors of $B_c$ to $D$-wave charmonia ${\psi }_J$ ($J=1,2,3$) and ${\eta }_{c2}$ are analyzed within the framework of three-point QCD sum rules. With the estimated vector and axial vector form factors, we study the decay widths and branching ratios of semileptonic decays $B_c\to {\psi }_{J}l\overline{{\nu }_l}$ and $B_c\to {\eta }_{c2}l\overline{{\nu }_l}$. Our results indicate that the semileptonic decay branching ratios of $B_c$ to $D$-wave charmonia decreases as the total angler momentum of the final state $D$-wave charmonia increases. For decay processes $B_c\to {\psi }_{1}l{\bar{\nu }}_l$, $B_c\to {\psi }_2[{\eta }_{c2}]l{\bar{\nu }}_l$ and $B_c\to {\psi }_{3}l{\bar{\nu }}_l$, the branching ratios can reach the order $10^{-3}$, $10^{-4}$ and $10^{-5}$, respectively, which can provide a valuable reference for future experimental measurements for $B_c$ meson by LHCb collaboration. Furthermore, these results also can provide useful information to study the properties of $B_c$ meson and $D$-wave charmonia.

   hep-phPLB(2026)·3 citations
7. 07*

   Prospects for compact hexaquarks under the limitation imposed by quark confinement

   Wen-Xuan Zhang🇨🇳 · Wen-Nian Liu🇨🇳 · Duojie Jia🇨🇳

   The limitation of flavor constituents for compact multiquarks is crucial for understanding the strong interaction at the low energy scale. Utilizing the MIT bag model that incorporates perturbative interactions and confinement energy $E_{\mathrm{CON}}$, we derive a critical bag radius $R_c=5.61$GeV${}^{-1}$ from the condition $E_{\mathrm{CON}}<0$ at zero temperature and zero baryon density, which aligns with the string-breaking distance of 1.2--1.4fm. Applying this framework to 6-, 7-, and 8-quark systems, we find the bag radii $R_0$ to be highly sensitive to relativistic effects from light quarks, leading to the exclusion of most heavy-light flavor configurations (e.g., $n^3{\bar{c}}^3$, $n^3\bar{n}{\bar{c}}^2$) due to positive $E_{\mathrm{CON}}$ and radii exceeding the critical radius. Color-spin wavefunctions are constructed using Young tableaux to evaluate interaction matrices and OZI-superallowed decays. Broad decay widths in fully heavy systems for OZI-superallowed modes could arise from wavefunction overlaps due to heavy flavor symmetry, suggesting possible narrow widths for $nnb\bar{b}\bar{b}\bar{b}$ and $nnn\bar{b}\bar{b}\bar{b}$ hexaquarks. This phenomenological approach provides insights into the limitations on multiquarks imposed by confinement. It recommends experimental searches at LHCb for these states.

   hep-phPRD(2025)·1 citation
8. 08*

   Revisit of the electromagnetic correction to $\tau \to \pi \pi {\nu }_{\tau }$ and its implication for muon $g-2$ based on $\tau$ data

   Zhi-Xin Li🇨🇳 · Ao Li🇨🇳 · Jin Hao🇨🇳 · Chun-Gui Duan🇨🇳 · Zhi-Hui Guo🇨🇳

   In this work we focus on the evaluation of the leading-order hadronic vacuum polarization contribution from the $\pi \pi$ channel to the muon anomalous magnetic moment $a_{\mu }$ by using the experimental $\tau \to \pi \pi {\nu }_{\tau }$ data. The isospin breaking corrections play the decisive role in this approach of computing $a_{\mu }$. One of such important isospin breaking sources is the long-distance electromagnetic correction factor $G_{\mathrm{EM}}$ of the $\tau \to \pi \pi {\nu }_{\tau }$ process from the real photon radiation. The latter effect can be calculated from the $\tau \to \pi \pi {\nu }_{\tau }\gamma$ amplitude, which is revised in this work within the resonance chiral theory by simultaneously including the even-intrinsic-parity and odd-intrinsic-parity resonance operators. We update the determination of the only unknown resonance coupling through the $\omega \to {\pi }^0{\pi }^0\gamma$ decay by including contributions from both the vector and scalar resonances. By taking other remaining contributions from the muon $g-2$ White Paper 2025, we further revise the complete value of $a_{\mu }$, which turns out to deviate from the newest world average result after Fermilab's measurement at the level of 2.7 $\sigma$.

   hep-phPRD(2026)·3 citations
9. 09*

   Qubit entanglement from forward scattering

   Kamila Kowalska🇵🇱 · Enrico Maria Sessolo🇵🇱

   In the context of entanglement in relativistic $2\to 2$ scattering described by a perturbative $S$-matrix, we derive analytically the concurrence for a mixed final state of two qubits corresponding to a discrete quantum number of the scattered particles. The qubit density matrix is obtained by tracing the momentum degrees of freedom out of the full density matrix of the scattered system. Given an initial product state, the derived concurrence depends at the leading order on the real part of the inelastic forward amplitude and the initial state only. We also point out that the real part of the forward amplitude provides a subleading correction to the linearized entropy, reducing it by an amount that, for a computational-basis state, is equivalent to the relative entropy of coherence. We illustrate our findings with two examples of phenomenological interest: high-energy scattering of two scalar fields in the two-Higgs doublet model, and high-energy electron-positron annihilation.

   hep-phhep-thquant-phJHEP(2026)·13 citations
10. 10*

    Mass Spectra of $qq\bar{q}\bar{q}$, $ss\bar{s}\bar{s}$ and $qq\bar{s}\bar{s}$ Tetraquarks using Regge Phenomenology

    Vandan Patel🇮🇳 · Juhi Oudichhya🇮🇳 · Ajay Kumar Rai🇮🇳

    In this paper, we explore the mass spectra of $qq\bar{q}\bar{q}$, $ss\bar{s}\bar{s}$ and $qq\bar{s}\bar{s}$ tetraquarks by employing Regge phenomenology. We calculate the range for ground state masses of $qq\bar{s}\bar{s}$ tetraquarks, and estimate the Regge parameters for their trajectories in $(J,M^2)$ plane. Using these Regge parameters we have calculated range for the excited state masses of $qq\bar{q}\bar{q}$, $ss\bar{s}\bar{s}$ and $qq\bar{s}\bar{s}$ tetraquarks in $(J,M^2)$ plane. Also, we have investigated the mass spectra of $qq\bar{q}\bar{q}$, $ss\bar{s}\bar{s}$ and $qq\bar{s}\bar{s}$ tetraquarks for their excited radial states in $(n,M^2)$ plane. We predict the potential quantum numbers of some newly observed experimental states, which necessitate additional validation, and assess the higher orbital and radial excited states that may be identified in the near future. The obtained mass relations and mass values of tetraquarks can be useful in future experimental searches and the spin-parity assignment of these states. Our findings provide valuable insights into the structure and properties of tetraquarks, contributing to the broader understanding of Quantum Chromodynamics (QCD).

    hep-phEPJA(2025)·8 citations
11. 11*

    Subleading Twist-3 Gluon Generalized Parton Distributions in the Light-Front Model

    Parashmani Thakuria🇮🇳 · Madhurjya Lalung🇮🇳 · Jayanta Kumar Sarma🇮🇳

    We present a calculation of the twist-3 generalized parton distributions (GPDs) for gluons in the proton. Our analysis is performed within a light-front constituent model where the proton is treated as a two-body state of a spin-1 gluon and a spin-1/2 spectator system. The requisite light-front wave functions are derived from the soft-wall AdS/QCD correspondence. We compute the complete set of twist-3 gluon GPDs over a broad kinematic range. The corresponding distributions in impact parameter space are obtained via Fourier transform, revealing the transverse spatial distribution of gluons. Furthermore, we evaluate the contribution of these GPDs to the gluon kinetic orbital angular momentum (OAM) and compare our findings with other theoretical predictions.

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

    Dirac neutrino and dark matter in left-right symmetric models

    Shohei Okawa🇰🇷 · Yuji Omura🇯🇵 · Keyun Wu🇪🇸

    We study neutrino mass generation and dark matter in a left-right symmetric model. The model is based on an $SU(3{)}_c\times SU(2{)}_L\times SU(2{)}_R\times U(1{)}_{B-L}$ gauge theory with a softly broken parity symmetry. Masses of the charged leptons and neutrinos are generated radiatively at one-loop and three-loop level respectively, through their interactions with newly introduced neutral fermion and scalar particles. A mass hierarchy of those new particles is required to reproduce the observed patterns of the charged lepton spectrum and neutrino oscillation data. The resulting light particles, whose mass can be as light as GeV, serve as good dark matter candidates. The phenomenology of such dark matter candidates is governed by their interactions to left- or right-handed neutrinos. We study physics of dark matter with several benchmark parameter sets that reproduce the realistic neutrino mass matrix structure, and identify viable parameter spaces.

    hep-phJHEP(2026)·1 citation
13. 13*

    Improving on the Pythia modelling of equal-scale multi-parton distribution functions

    Oleh Fedkevych🇺🇸 · Jonathan R. Gaunt🇬🇧 · Seonagh Smith🇬🇧

    Multi-parton distribution functions (mPDFs) are non-perturbative objects that are important in the prediction of multiple scattering rates at hadron colliders. In the case where the scales associated with all partons in the mPDF are the same, we have two theoretical constraints on the mPDF. These are symmetry in exchange of the parton indices, and the number and momentum sum rules. In a previous publication (arXiv:2208.08197) we found that the equal-scale mPDFs from the Pythia model could not satisfy both of these constraints simultaneously. In this paper we introduce an algorithm for constructing equal-scale mPDFs that is based on the Pythia procedure but has three additional modifications, such that it yields symmetric mPDFs that should satisfy the sum rules to an improved extent. We test the construction for the case of the double and triple parton distribution functions (dPDFs and tPDFs), finding that the sum rules are obeyed to within 10% over the vast majority of the phase space for the scales tested (and deviations only being mildly above this level). We use our dPDFs to compute rapidity asymmetries for same-sign WW and ZZ production via double parton scattering, and compare the results to predictions obtained using Pythia and the GS09 dPDFs of arXiv:0910.4347.

    hep-phJHEP(2026)·5 citations
14. 14*

    On the threshold behaviour of heavy top production

    Torbjörn Sjöstrand🇸🇪

    The observation of an excess of ttbar production in the threshold region, by CMS and ATLAS, has been interpreted as a toponium contribution, i.e. from below-threshold ttbar virtual states. The news here is the nontrivial experimental extraction of such a signal, not its existence as such. Indeed, already 35+ years ago an NRQCD Green's function approach was used to model the above- and below-threshold production of ttbar pairs in pp/ppbar collisions. The relevant cross section equations from that study are now (re-)implemented in the Pythia 8 event generator. While the above-threshold part is straightforward, the physical interpretation and modelling of below-threshold events is nontrivial, and a final prescription is cross-checked against two simpler ones. Cross sections and some event properties are presented.

    hep-phPoS(2026)·7 citations
15. 15*

    Mixed WIMP-FIMP scenario in a two-component dark matter model

    XinXin Qi🇨🇳 · Hao Sun🇨🇳

    We consider the mixed WIMP-FIMP scenario in a two-component dark matter model with $Z_2\times Z_4$ symmetry, where a singlet scalar $S$ and a Majarano fermion $\chi$ are introduced as dark matter candidates. We also introduce another singlet scalar $S_0$ with a non-zero vacuum expectation value to the SM so that the fermion dark matter can obtain mass after spontaneous symmetry breaking. Either $S$ or $\chi$ relic density can be generated via the "Freeze-out" mechanism. In contrast, the other DM candidate relic density is obtained by the "Freeze-in" mechanism, and we therefore have two different cases. In the case of $\chi$ as WIMP and $S$ as FIMP, we perform random scans to estimate the allowed parameter space consistent with the dark matter constraint. The results show that this case is viable over a wide range of dark matter masses with the Yukawa coupling of $S_0$ and $\chi$ should be larger than 1. Instead, for the case of $S$ as WIMP and $\chi$ as FIMP, the viable parameter space is more constrained by the direct detection experiements, and we have two regions with $m_S\approx 62.5$ GeV and $m_S>400$ GeV under the constraints, which is consistent with the singlet scalar DM result but the scalar DM mass can be as low as a few hundred GeV for the heavy mass region in the model.

    hep-phJCAP(2026)·3 citations
16. 16*

    Heavy flavor particle production in p+p collisions at the CERN Large Hadron Collider energies

    Tonmoy Sharma🇮🇳 · Banajit Barman🇮🇳 · Buddhadeb Bhattacharjee🇮🇳

    The study of heavy-flavored baryon and meson production in proton-proton (pp) collisions provides crucial insight into the hadronization mechanisms of Quantum Chromodynamics (QCD). In this work an attempt has been made to describe the existing ALICE and LHCb results on the $p_{\mathrm{T}}$-differential production cross-section of ${\Lambda }_c^{+}$, $D^0$, ${\Lambda }_b^0$ and $B^0$ (${\bar{B}}^0$), and $p_{\mathrm{T}}$-dependent ${\Lambda }_c^{+}/D^0$ and ${\Lambda }_b^0/B^0({\bar{B}}^0)$ ratios, in light of the color-string junction inspired PYTHIA-8.314 model. A comparison of the results obtained with various datasets generated with different tuning parameters and the existing experimental results of ALICE and LHCb at $\sqrt{s}=7$ and $13$ TeV underlines the relevance of string-junction dynamics in heavy-flavored particle production. The results of the present investigation reveal that while stopping the junction-antijunction reconfiguration in the non-perturbative PYTHIA-8.314 model successfully describes the considered ALICE experimental observables of the charm sector, on the other hand, allowing junction-antijunction reconfiguration, keeping other fragmentation parameters the same, better describes the LHCb experimental observables of both charm and bottom sectors.

    hep-ph0 citations
17. 17*

    Overview of the latest developments in understanding the initial state and thermalization

    Kirill Boguslavski🇦🇹

    A proper description of the non-equilibrium matter preceding the quark-gluon plasma (QGP) in heavy-ion collisions and its observable consequences remain a major theoretical challenge, while at the same time offering new opportunities for experimental exploration. In these proceedings, I provide an overview of studies presented in talks and posters at Quark Matter 2025 on this topic. We will focus on the latest developments regarding the features and the numerical description of the non-equilibrium pre-QGP matter, as well as the potential to use hard probes as a means to study the hydrodynamization dynamics of the QCD plasma.

    hep-phhep-exhep-thnucl-thEPJ Web Conf.(2026)·0 citations
18. 18*

    Integral of the double-emission eikonal function for two massive emitters at an arbitrary angle

    Ming-Ming Long🇩🇪 · Kirill Melnikov🇩🇪 · Andrey Pikelner🇩🇪

    We present a semi-analytic calculation of the integrated double-emission eikonal function of two massive emitters whose momenta are at an arbitrary angle to each other. This result is needed for extending the nested soft-collinear subtraction scheme arXiv:1702.01352 to processes with massive partons.

    hep-phJHEP(2026)·0 citations
19. 19*

    Resonant Singly Heavy Pentaquarks in the MIT Bag Model: Mass Spectra and Strong Decays

    Wen-Nian Liu🇨🇳 · Wen-Xuan Zhang🇨🇳 · Cheng-Jie Wang🇨🇳 · Kai-Kai Zhang🇨🇳 · Fu-Quan Dou🇨🇳

    Exploring the limits of color interactions in multiquark states is an important topic. Based on the bag confinement picture of hadrons, we find that for singly heavy pentaquarks, the bag confinement radius precisely falls within the range of color interaction limits provided by lattice QCD, approximately 1.17--1.29$\text{fm}$. This leads us to believe that singly heavy pentaquark states have the potential to form resonant states. Inspired by singly heavy baryons, we consider the mirror pentaquarks of singly heavy baryons. Furthermore, we adopt the MIT bag model, taking into account chromomagnetic and color-electric interactions between heavy and strange quarks, to calculate the mass spectrum of singly heavy pentaquarks configured as $qqqQ\bar{q}$ and analyze the stability of their S-wave two-body strong decays. We show that for the singly heavy pentaquark system, the masses are generally about $500\text{MeV}$ higher than the corresponding mirror baryon ground state masses, which is consistent with conclusions drawn from chiral methods. We also provide a mass mapping relationship between singly heavy pentaquarks and singly heavy baryons based on light quark flavor symmetry. The analysis of strong decays indicates that these singly heavy pentaquarks are unstable with respect to strong decays, which is consistent with our initial hypothesis.

    hep-phEPJC(2026)·2 citations
20. 20*

    One-Loop Effects in the Neutrino Matter Potential and Implications for Non-Standard Interactions

    Jihong Huang🇨🇳 · Tommy Ohlsson🇸🇪 · Sampsa Vihonen🇸🇪 · Shun Zhou🇨🇳

    In this work, we emphasize that it is necessary to take into account one-loop corrections of $2.0\%$ to the neutrino matter potential in the precision measurements of neutrino oscillation parameters and in the experimental searches for new physics beyond the Standard Model. With the numerical simulation of the DUNE experiment, we study how radiative corrections to the matter potential affect neutrino oscillation probabilities, and thus, the event rates in the presence of neutrino non-standard interactions (NSIs). We find that neglecting one-loop corrections may lead to wrong conclusions for the discovery of NSIs. The implications for the determination of neutrino mass ordering and constraints on the NSI parameters in future long-baseline accelerator neutrino experiments are explored in a quantitative way.

    hep-phPRD(2025)·2 citations
21. 21*

    Curvature-Aware Deep Learning for Vector Boson Fusion: Differential Geometry, Physics-Inspired Features, and Quantum Method Limitations

    Alibordi Muhammad🇵🇱

    Particle physics classification often assumes flat geometry, ignoring the curved statistical structure of collision data. We present a geometric framework for Vector Boson Fusion Higgs classification that combines physics-inspired observables with product manifold neural networks. The method unifies Euclidean, hyperbolic, and spherical representations to capture nonlinear correlations among kinematic features. Geometric embedding yields measurable improvements over flat baselines, demonstrating that curvature-aware architectures recover information lost in standard approaches. The study highlights how incorporating geometric structure enhances discrimination power in high-energy collision data.

    hep-ph0 citations
22. 22*

    Internal multiplicity distributions of jets from nonlinear evolution within the jet function framework

    Pi Duan🇨🇳 · Weiyao Ke🇨🇳 · Guang-You Qin🇨🇳 · Lei Wang🇨🇳

    Jets selected with high internal charged-particle multiplicity exhibit markedly different substructure patterns compared to inclusive jet samples. Such correlations motivate a systematic study of jet observables as a function of the normalized multiplicity, $\nu =N_{\mathrm{ch}}/⟨N_{\mathrm{ch}}⟩$. In this work, we develop a theoretical framework for the full charged-particle multiplicity distribution of exclusive and inclusive jets, formulated within the jet-function approach. The hard production and jet function are evaluated at NLO+LL${}_R$ accuracy. The internal parton dynamics governing the multiplicity distribution are described by coupled nonlinear branching equations with angular ordering, supplemented by a nonperturbative modeling term that accounts for hadron-level effects. The resulting predictions are validated against \textsc{Pythia8} simulations and compared with CMS data. We examine the effects of both nonperturbative and perturbative components in shaping the multiplicity distribution, and show that Koba--Nielsen--Olesen (KNO) scaling is notably violated in the region $\nu >2$ in the full solution, with a trend consistent with Monte Carlo results. This framework that numerically solves the nonlinear multiplicity evolution goes beyond DLA-like approximations and reproduces key features seen in event generators, providing a solid foundation for future investigations of multiplicity -- conditioned jet substructure within the jet function formalism.

    hep-phJHEP(2026)·3 citations
23. 23*

    High-Energy Evolution of Power-Suppressed Amplitudes

    Maximilian Delto🇨🇭 · Alexander Penin🇨🇦 · Lorenzo Tancredi🇩🇪

    We present a new class of evolution equations which govern the high-energy behavior of power-suppressed scattering amplitudes. The equations can be viewed as a renormalization group flow with respect to the relevant effective field theory cutoff. A distinct feature of the method is in the use of a multidimensional cutoff to separate the relevant scales in problems characterized by a complex factorization structure. By adjusting the renormalization group variables to the geometry of the effective theory modes, our method naturally extends to a broad spectrum of physical problems including massive, massless, small, and wide angle scattering. We present applications to the benchmark processes of electron-positron forward annihilation and light quark mediated Higgs boson production/decays.

    hep-phPRL(2026)·4 citations
24. 24*

    Probing the Higgs potential at a Photon Collider

    Marten Berger🇩🇪 · Johannes Braathen🇩🇪 · Gudrid Moortgat-Pick🇩🇪 · Georg Weiglein🇩🇪

    A $\gamma \gamma$ collider, either in conjunction with an $e^{+}{e}^{-}$ linear collider or as a stand-alone facility, offers a very attractive Higgs physics programme at relatively low centre-of-mass (c.m.) energies. While the Higgs boson that has been discovered at the LHC can be studied in detail in resonant production at 125~GeV, a c.m.\ energy as low as 280~GeV can probe the Higgs potential via the Higgs pair production process providing access to the trilinear Higgs-boson self-coupling. High polarisation of the photon beams (produced via Compton back-scattering) can be achieved and adjusted by flipping the polarisation of the incident laser. The prospects for exploring the Higgs pair production process at a $\gamma \gamma$ collider are assessed by comparing different running scenarios utilising different types of the incident laser. The possibility to use photon polarisations for disentangling different kinds of contributions to the Higgs pair production process is emphasised.

    hep-phhep-ex7 citations
25. 25*

    A comprehensive study of ${\Lambda }_c^{-}\to \Lambda (\to p\pi ){\mu }^{-}{\bar{\nu }}_{\mu }$ incorporating SMEFT implications and right-handed neutrino

    Priyanka Boora🇮🇳 · Siddhartha Karmakar🇮🇳 · Dinesh Kumar🇮🇳 · Kavita Lalwani🇮🇳

    We present a comprehensive analysis of the decay ${\Lambda }_c^{-}\to \Lambda (\to p\pi ){\mu }^{-}{\bar{\nu }}_{\mu }$ within a model-independent effective field theory framework. Previous studies have been restricted to the three-body decay ${\Lambda }_c^{+}\to \Lambda {\mu }^{+}{\nu }_{\mu }$ and considered only left-handed neutrinos within the Low-Energy Effective Theory (LEFT). In this work, we extend the analysis to the complete four-body angular distribution for the first time, incorporating the indirect constraints implied by the Standard Model Effective Field Theory (SMEFT) on the LEFT Wilson coefficients. We also include the effects of right-handed neutrino (RHN) operators, enabling a unified treatment of both left- and right-handed neutrino interactions in the $c\to s\mu {\nu }_{\mu }$ transition. Using the global bounds derived from LEFT observables and their SMEFT correlations, we study the impact of allowed new-physics scenarios on a variety of observables, including differential decay rates, forward-backward asymmetries, polarization asymmetries of the final-state hadron and lepton, and the angular coefficients (${\mathcal{M}}_0$ to ${\mathcal{M}}_9$) in the 4-body angular distribution. Our analysis reveals significant deviations from the Standard Model in the observables ${\mathcal{P}}_L^{\Lambda }$ and ${\mathcal{M}}_1$ for $C_{RL}^V$ and $C_{RR}^V$, and striking $T$-odd effects in ${\mathcal{M}}_7$ for complex $C_{RL}^V$. These features provide sensitive probes of vector-type new physics, such as leptoquark or right-handed current models. The predicted patterns can be tested in forthcoming measurements at BESIII, LHCb, and Belle II, where polarization-sensitive observables in ${\Lambda }_c$ decays are becoming experimentally accessible.

    hep-phPRD(2026)·1 citation
26. 26*

    Barnett effect as a new source of magnetic field in heavy-ion collisions

    Dushmanta Sahu🇲🇽

    The Barnett effect is a fundamental magnetomechanical phenomenon in which a ferromagnetic material becomes magnetized under rotation. Using a hadron resonance gas (HRG) model under rigid rotation, we compute the Barnett magnetization ($M_{\mathrm{Barnett}}$) and show that it produces a magnetic field ($B_{\text{ind}}$) comparable in magnitude to the well-known external field ($B_{\text{ext}}$) from spectator protons at low energy heavy-ion collisions. This finding establishes the Barnett effect as a previously overlooked but essential source of magnetization and magnetic field in the heavy-ion collisions, with profound implications for understanding spin dynamics and anomalous transport in quantum chromodynamics under extreme rotation.

    hep-phhep-thnucl-thPLB(2026)·5 citations
27. 27*

    NeoPDF: A fast interpolation library for collinear and transverse momentum-dependent parton distributions

    Tanjona R. Rabemananjara🇳🇱

    We present NeoPDF, an interpolation library that supports both collinear and transverse momentum-dependent parton distribution functions. NeoPDF is designed to be fast and reliable, with modern functionalities that target both current and future hadron collider experiments. It aims to address the shortcomings of existing interpolation libraries while providing additional features to support generic non-perturbative functions. Some of the features include a new interpolation based on Chebyshev polynomials, as well as the ability to interpolate along the nucleon number $A$, the reference strong coupling ${\alpha }_s(M_Z)$, and the parton's intrinsic transverse momentum $k_T$. NeoPDF implements its own file format using binary serialisation and lossless compression, prioritising speed and efficiency. A no-code migration design is provided for LHAPDF in order to remove the frictions associated with transitioning to NeoPDF. The library is written in Rust with interfaces for various programming languages such as Fortran, C, C++, Python, and Mathematica. We benchmark NeoPDF against LHAPDF and TMDlib for various sets and show that it is both fast and accurate.

    hep-phhep-exEPJC(2025)·1 citation
28. 28*

    Rapid event extraction and tensorial event adaption: Libraries for efficient access and generic reweighting of parton-level events and their implementation in the MadtRex module

    Stefan Roiser🇨🇭 · Robert Schöfbeck🇦🇹 · Zenny Wettersten🇨🇭

    We present Rex and teaRex, C++17 libraries for efficient management of parton-level hard scattering event information and completely generic reweighting of such events, respectively. Rex is primarily an interfacing and I/O library for Les Houches Event format files and provides an internal event format designed with data parallelism in mind, and teaRex extends this format to provide full parton-level reweighting functionality with minimal code needing to be written by the end user. These libraries serve as the foundation for the MadtRex reweighting module for MadGraph5_aMC@NLO, extending the functionality of the CUDACPP plugin to allow for data-parallel model-generic leading order parameter reweighting on SIMD-enabled CPUs and SIMT GPUs, speeding up reweighting by more than two orders of magnitude compared to MadGraph5_aMC@NLO running on the exact same hardware while providing trivial scalability to larger and distributed systems.

    hep-phhep-exphysics.acc-phEPJC(2025)·2 citations
29. 29*

    Intrinsically Quantum Effects of Axion Dark Matter are Undetectable

    Yunjia Bao🇺🇸 · Dhong Yeon Cheong🇰🇷 · Nicholas L. Rodd🇺🇸 · Joey Takach🇺🇸 · Lian-Tao Wang🇺🇸 · Kevin Zhou🇺🇸

    Is the usual treatment of axion dark matter as a classical field reliable? We show that the answer is subtle: the axion field could well be in a quantum state that has no complete classical description, but realistic detectors cannot tell the difference. To see this, we solve a fully quantum model of axion detection using quantum optics techniques. We show that intrinsically quantum effects are washed out by mode averaging or small amounts of noise, and significantly suppressed by the weakness of the axion coupling. Our work exemplifies that there should always be a classical analog for axion dark matter effects, extends to other wave (ultralight) dark-matter candidates, and gives a general method to compute the effects of exotic dark-matter states.

    hep-phastro-ph.COhep-exhep-th+1PRL(2026)·6 citations
30. 30*

    Testing the arrow of time at the cosmo collider

    Shuntaro Aoki🇯🇵 · Alessandro Strumia🇮🇹

    Normal particles carry a microscopic arrow of causality. Lee-Wick ghosts carry the reversed arrow, mediating characteristic collider signals in flat space: opposite-sign scattering amplitudes that violate positivity bounds; acausality on time scales set by their negative decay rate. During inflation, the corresponding cosmo-collider ghost signals are: opposite-sign non-Gaussianities; Boltzmann-unsuppressed local oscillatory signals without their non-local counterparts; IR-enhanced bi-spectrum and power spectrum, depending on the dimension of the interaction operator, which decreases if the ghost decay rate is comparable to the Hubble rate.

    hep-phastro-ph.COgr-qchep-thJCAP(2026)·10 citations
31. 31*

    DAMA/LIBRA and dark matter: decisive tension or contrived cancellation

    Giorgio Busoni🇦🇺 · Jonathan M. Cornell🇺🇸 · Will Handley🇬🇧 · Felix Kahlhoefer🇩🇪 · Anders Kvellestad🇳🇴 · Masen Pitts🇨🇦 · Lauren Street🇺🇸 · Aaron C. Vincent · Martin White🇦🇺

    The ANAIS-112 and COSINE-100 experiments were constructed to test the long-observed dark matter-like annual modulation signal reported by DAMA. While they have reported null results in their annual modulation search, it remains possible that the combined effects of quenching, efficiency, resolution and binning could transform a common nuclear recoil rate into a signal that is visible in some detectors but not others. We assess the tension between DAMA/LIBRA and these latest experiments, under a range of hypotheses ranging from physical to general parameterisations of a common nuclear recoil input. We find that, in the most physically-motivated cases, the tension between DAMA and these other NaI experiments exceeds 5$\sigma$. Lowering the tension to reasonable values requires significant tuning, such as overfitting with large numbers of free parameters, and opposite-sign modulation between recoil signals on sodium versus iodine.

    hep-phJCAP(2026)·1 citation
32. 32*

    Spectral functions in Minkowski quantum electrodynamics from neural reconstruction

    Rodrigo Carmo Terin🇪🇸

    We study neural reconstructions of quenched rainbow quantum electrodynamics (QED) Dyson--Schwinger benchmarks in Minkowski-related kinematics. Using the dispersive formulation as motivation, we separate the Euclidean Fukuda--Kugo equation, the spectral unitary equations, and the modified unitary equations. The Fukuda--Kugo benchmark is solved directly and shows the expected zero crossing above the critical region ${\alpha }_c=\pi /3$. Neural reconstructions with free output reproduce this behavior, while positivity-constrained ansätze fail in the supercritical regime. Thus, spectral positivity should be treated as a diagnostic of the Lehmann representation, not imposed blindly as a neural constraint.

    hep-phcs.LGhep-lathep-th2 citations
33. 33*

    Atmospheric pion, kaon, and muon fluxes for sub-orbital experiments

    Diksha Garg🇺🇸 · Laksha Pradip Das🇺🇸 · Mary Hall Reno🇺🇸

    Cosmic rays interacting with the Earth's atmosphere generate extensive air showers, which produce Cherenkov, fluorescence and radio emissions. These emissions are key signatures for detection by ground-based, sub-orbital, and satellite-based telescopes aiming to study high energy cosmic ray and neutrino events. However, detectors operating at ground and balloon altitudes are also exposed to a background of atmospheric charged particles, primarily pions, kaons, and muons, that can mimic or obscure the signals from astrophysical sources. In this work, we use coupled cascade equations to calculate the atmospheric pion, kaon and muon fluxes reaching detectors at various altitudes. Our analysis focuses on energies above 10 GeV, where the influence of the Earth's magnetic field on particle trajectories is minimal. We provide angular and energy-resolved flux estimates and discuss their relevance as background for extensive air shower detection. Our results are potentially relevant for interpreting data from current and future balloon-borne experiments such as EUSO-SPB2 and for refining trigger and veto strategies in Cherenkov and fluorescence telescopes.

    ↳ astro-ph.HEhep-phAstropart.Phys.(2026)·1 citation
34. 34*

    Semiclassical treatment of bottomonium suppression and regeneration in $p+\mathrm{Pb}$ collisions

    Sabin Thapa🇺🇸 · Biaogang Wu🇺🇸 · Ramona Vogt🇺🇸 · Ralf Rapp🇺🇸

    We study bottomonium suppression in $p+\mathrm{Pb}$ relative to $p+p$ collisions at center-of-mass energies of $\sqrt{s_{NN}}=5.02$ and 8.16~TeV. Specifically, we combine cold nuclear matter effects (nuclear modifications of the parton densities, energy loss and momentum broadening) with those from hot nuclear matter (suppression and regeneration) by implementing the formation of a quark-gluon plasma in hydrodynamic simulations. Bottomonium transport in the quark-gluon plasma is evaluated semiclassically, employing two different reaction rates. The first includes quasi-free inelastic scattering and gluo-dissociation employing a perturbative coupling to the medium. The second is based on in-medium $T$-matrix calculations where the input potential is constrained by lattice quantum chromodynamics to extract the bottomonium masses and dissociation rates. These semiclassical results are compared to previous calculations in an open quantum systems approach and to the experimental data. Predictions for ${\chi }_b$ suppression at $\sqrt{s_{NN}}=8.16$~TeV are also presented.

    ↳ nucl-thhep-phPRD(2026)·4 citations
35. 35*

    Effects of the ekpyrotic mechanism on inflationary phase in loop quantum cosmologies

    Christian Brown🇺🇸 · Jared Fier🇺🇸 · Brian Phillips🇺🇸 · Gerald Cleaver🇺🇸 · Anzhong Wang🇺🇸

    In bouncing cosmological models, either classical or quantum, the big bang singularity is replaced by a regular bounce. A challenging question in such models is how to keep the shear under control in the contracting phase, as it is well-known that the shear grows as fast as $1/a^6$ toward the bounce, where $a$ is the average expansion factor of the universe. A common approach is to introduce a scalar field with an ekpyrotic-like potential which becomes negative near the bounce, so the effective equation of state of the scalar field will be greater than one, whereby it dominates the shear in the bounce region. As a result, a homogeneous and isotropic universe can be produced after the bounce. In this paper, we study how the ekpyrotic mechanism affects the inflationary phase in both loop quantum cosmology (LQC) and a modified loop quantum cosmological model (mLQC-I), because in these frameworks inflation is generic without such a mechanism. After numerically studying various cases in which the potential of the inflaton consists of two parts, an inflationary potential and an ekpyrotic-like one, we find that, despite the fact that the influence is significant, by properly choosing the free parameters involved in the models, the ekpyrotic-like potential dominates in the bounce region, during which the effective equation of state is larger than one, so the shear problem is resolved. As the time continuously increases after the bounce, the inflationary potential grows and ultimately becomes dominant, resulting in an inflationary phase. This phase can last long enough to solve the cosmological problems existing in the big bang model.

    ↳ gr-qcastro-ph.COhep-phhep-thEPJC(2026)·3 citations
36. 36*

    A quantum information method for early universe with non-trivial sound speed

    Shi-Cheng Liu🇨🇳 · Lei-Hua Liu🇨🇳 · Bichu Li🇨🇳 · Hai-Qing Zhang🇨🇳 · Peng-Zhang He🇨🇳

    Many quantum gravitational frameworks, such as DBI inflation, k-essence, and effective field theories obtained by integrating out heavy modes, can lead to a non-trivial sound speed. Meanwhile, our universe can be described as an open system. Under the non-trivial sound speed, we employ the method of open quantum systems combined with Arnoldi iterations to study the Krylov complexity throughout the early universe, including the inflationary, radiation-dominated, and matter-dominated epochs. A key ingredient in our analysis is the open two-mode squeezed state formalism and the generalized Lanczos algorithm. To numerically compute the Krylov complexity, we are the first time to derive the evolution equations for the parameters $r_k$ and ${\varphi }_k$ within an open two-mode squeezed state. Our results indicate that the Krylov complexity exhibits a similar trend in both the standard case and the case with non-trivial sound speed. To distinguish between these two scenarios, we also investigate the Krylov entropy for completeness. The evolution of the Krylov entropy shows a clear difference between the standard case and the non-trivial sound speed case. Furthermore, based on the behavior of the Lanczos coefficients, we find that the case of non-trivial sound speed behaves as a maximally chaotic system. However, our numerical results suggest that the Krylov complexity does not saturate to a constant value due to the huge expansion of spacetime background. This study offers a new perspective for exploring the early universe through the quantum information.

    ↳ gr-qcastro-ph.COhep-phhep-th+1Fortsch.Phys.(2026)·9 citations
37. 37*

    Quantum computing for heavy-ion physics: near-term status and future prospects

    João Barata🇨🇭

    We discuss recent advances in applying Quantum Information Science to problems in high-energy nuclear physics. After outlining key developments, open challenges, and emerging connections between these disciplines, we highlight recent results on the study of matter states, hard probes, and spin correlations using novel quantum technologies. This work summarizes the corresponding presentation delivered at the Quark Matter 2025 conference in Frankfurt, Germany.

    ↳ quant-phhep-phnucl-thEPJ Web Conf.(2026)·1 citation
38. 38*

    Electromagnetic instability of vacuum with instantons in the holographic plasma

    Shao-cheng Hou🇨🇳 · Si-wen Li🇨🇳

    Using the gauge-gravity duality, we study the electromagnetic instability of vacuum with instantons in holographic plasma. The model we employ is the D(-1)-D3 brane system in which the D(-1)-branes correspond to the instantons in holography. To take into account the flavored quarks, the coincident probe D7-branes as flavors are embedded into the bulk geometry so that the effective electromagnetic Lagrangian with flavors corresponds to the action of the D7-branes according to gauge-gravity duality. We numerically evaluate the vacuum decay rate, the critical electric field and the V-A curve of the vacuum by using the D7-brane action with various values of the electromagnetic field. It implies the particles in the plasma acquire an effective mass in the presence of instantons as it is expected in the quantum field theory, and the plasma trends to become insulating when the electric field is small. This work reveals the relation between electromagnetic and instantonic properties of the vacuum in the plasma.

    ↳ hep-thhep-phquant-ph0 citations
39. 39*

    The Role of Acoustic Instability in Cosmic-Ray Self-Confinement

    Antonio Capanema🇧🇷 · Pasquale Blasi🇮🇹 · Emanuele Sobacchi

    Over the past decades, there has been growing observational and theoretical evidence that cosmic-ray-induced instabilities play an important role in both acceleration and transport of cosmic rays (CRs). For instance, the efficient acceleration of charged particles at supernova remnant shocks requires rapidly growing instabilities, so much so that none of the proposed processes seem sufficient to warrant acceleration to PeV energies. In this work, we investigate whether an acoustic instability triggered by the presence of a CR pressure gradient can lead to significant self-confinement of charged particles in the vicinity of shocks. We validate the expected growth rates and obtain the scale and energy of magnetic field perturbations induced by such system using magnetohydrodynamical simulations. Our results suggest a strong suppression of the diffusion coefficient for particles with Larmor radius around a thousandth of the precursor scale length.

    ↳ astro-ph.HEhep-phPoS(2025)·0 citations
40. 40*

    Neutrinogenic CMB spectral distortions

    Shao-Ping Li🇯🇵 · Jens Chluba🇬🇧

    Extra radiation injection after neutrino decoupling in the early Universe contributes to the effective number of neutrino species that can be constrained by the cosmic microwave background (CMB). However, any effective neutrino number itself cannot uniquely determine the underlying source. We argue that the degeneracy can be relaxed by CMB spectral distortions, which are caused by energy exchange between the extra radiation and photons. We consider neutrinogenic CMB spectral distortions, where extra energy is released in the form of neutrinos but still creates the CMB spectral distortions via electroweak interactions. The synergy between the effective neutrino number and CMB spectral distortions provides a complementary probe of hidden sectors that dominantly couple to neutrinos, opening up parameter space that can be targeted by joint CMB anisotropy and spectral distortion experiments.

    ↳ astro-ph.COhep-phPRD(2026)·5 citations
41. 41*

    On the universal content of the proper time flow in scalar and Yang-Mills theories

    Gabriele Giacometti🇮🇹 · Daniele Rizzo🇵🇱 · Dario Zappala🇮🇹

    We investigate the perturbative structure of the proper time renormalization group flow in scalar and Yang-Mills theories. Although the PT flow does not belong to the class of exact functional renormalization group equations, we show that it correctly reproduces the universal coefficients of the $\beta$-functions at one and two loops. For the $\mathrm{O}(\mathrm{N})$ scalar theory, we derive the one- and two-loop contributions to the running quartic coupling and also confirm the expected anomalous dimension. For the $\mathrm{SU}(\mathrm{N})$ Yang-Mills theory, using the background field method, we compute the gauge coupling renormalization recovering the correct two-loop $\beta$-function without generating any gauge-symmetry-violating term. These results highlight that, despite its limitations for reconstructing the full effective action, the PT flow retains the essential universal content of renormalization, accounting for its reliability in diverse applications ranging from statistical models to quantum gravity.

    ↳ hep-thhep-phPRD(2026)·10 citations
42. 42*

    Cosmic topology. Part IIb. Eigenmodes, correlation matrices, and detectability of non-orientable Euclidean manifolds

    Craig J. Copi🇺🇸 · Amirhossein Samandar🇺🇸 · Glenn D. Starkman🇺🇸 · Javier Carrón Duque🇪🇸 · Yashar Akrami🇪🇸 · Stefano Anselmi🇮🇹 · Andrew H. Jaffe🇬🇧 · Arthur Kosowsky🇺🇸 · Fernando Cornet-Gomez🇺🇸 · Johannes R. Eskilt🇳🇴 · Mikel Martin Barandiaran🇪🇸 · Deyan P. Mihaylov🇺🇸 and 4 other authors

    If the Universe has non-trivial spatial topology, observables depend on both the parameters of the spatial manifold and the position and orientation of the observer. In infinite Euclidean space, most cosmological observables arise from the amplitudes of Fourier modes of primordial scalar curvature perturbations. Topological boundary conditions replace the full set of Fourier modes with specific linear combinations of selected Fourier modes as the eigenmodes of the scalar Laplacian. In this paper we consider the non-orientable Euclidean topologies \E{7}--\E{10}, \E{13}--\E{15}, and \E{17}, encompassing the full range of manifold parameters and observer positions, generalizing previous treatments. Under the assumption that the amplitudes of primordial scalar curvature eigenmodes are independent random variables, for each topology we obtain the correlation matrices of Fourier-mode amplitudes (of scalar fields linearly related to the scalar curvature) and the correlation matrices of spherical-harmonic coefficients of such fields sampled on a sphere, such as the temperature of the cosmic microwave background (CMB). We evaluate the detectability of these correlations given the cosmic variance of the CMB sky. We find that in manifolds where the distance to our nearest clone is less than about $1.2$ times the diameter of the last scattering surface of the CMB, we expect a correlation signal that is larger than cosmic variance noise in the CMB. Our limited selection of manifold parameters are exemplary of interesting behaviors, but not necessarily representative. Future searches for topology will require a thorough exploration of the parameter space to determine what values of the parameters predict statistical correlations that are convincingly attributable to topology.[Abridged]

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2026)·7 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.