Tue·Sep 16, 2025Tuesday·September 16, 2025

1. 01*

   Glauber quark and gluon contributions to quark energy loss at next-to-leading order and next-to-leading twist

   Amit Kumar🇨🇦 · Gojko Vujanovic🇨🇦

   The higher-twist formalism is used at $O({\alpha }_s^2)$ to compute all possible medium-induced single-scattering emission kernels for an incoming highly energetic and virtual quark traversing the nuclear environment. The effects of the heavy-quark mass scale are taken into account [Phys. Rev. C 94, 054902 (2016)] both in the initial state as well as in the final state, along with interactions involving both in-medium Glauber gluons and quarks [Nucl. Phys. A 793, 128 (2007)], as well as coherence effects [Phys. Rev. C 105, 024908 (2022)]. As this study is a continuation of our work on medium-induced photon production [Phys. Rev. C 112, 025204 (2025)], the general factorization procedure for $e$-$A$ deep-inelastic scattering is still used. An incoming quark energy loss in the nuclear medium yields four possible scattering kernels $K_i$ with the following final states: (i) $q+g$, (ii) $g+g$, (iii) $q+{\bar{q}}^{\prime }$, where the quark $q$ may have a flavor different from the antiquark ${\bar{q}}^{\prime }$, and (iv) $q+q^{\prime }$, where, again, $q$ may have a flavor different from $q^{\prime }$. The collisional kernels include full phase factors from all non-vanishing diagrams and complete first-order derivative in the longitudinal direction ($k^{-}$) as well as second-order derivative in the transverse momentum ($k_{\perp }$) gradient expansion. Furthermore, in-medium parton distribution functions and the related jet transport coefficients have a hard transverse-momentum dependence (of the emitted quark or gluon) present within the phase factor.

   hep-phnucl-exnucl-thPRC(2026)·4 citations
2. 02*

   Trace-anomaly-subtracted $\sigma$-mass for Heavy Quarks and Matching from Lattice QCD

   Long Chen🇨🇳 · Cong Zhao🇨🇳

   We demonstrate that the leading IR-renormalon divergence in the perturbative pole mass of a massive quark resides entirely in the contribution from the trace anomaly of the energy-momentum tensor in QCD. Consequently, the recently proposed trace-anomaly-subtracted $\sigma$-mass definition for heavy quarks is not only scheme- and scale-invariant, hence unique for each flavor, but also free from the leading IR-renormalon ambiguity. We further derive a formula connecting this $\sigma$-mass to the perturbative pole mass, solely in terms of the QCD $\beta$-function, quark-mass anomalous dimension ${\gamma }_m$ and a proper rewritten form of the pole-to-$\overline{\mathrm{MS}}$ mass conversion factor. Utilizing this formula together with the ingredients available in the literature, we present the explicit five-loop result for the perturbative relationship between the $\sigma$-mass and the perturbative pole mass in QCD under the approximation of keeping only a single quark massive. Furthermore, we outline how $\sigma$-mass for a heavy quark can in principle be determined from lattice QCD through an intermediate regularization-independent renormalization and continuum perturbative matching, for which we analyze the matching factor through four loops with appealing features revealed. Given the aforementioned theoretical merits of this mass definition and the availability of high-precision conversion relations as well as the feasibility of direct extraction from lattice QCD, it is well suited for acting as a promising candidate reference scheme for comparing or combining quark masses of the same flavor obtained in different schemes.

   hep-phhep-lathep-th3 citations
3. 03*

   Collective motion in the massive Schwinger model via Tensor Network

   Haiyang Shao🇨🇳 · Shile Chen🇨🇳 · Shuzhe Shi🇨🇳

   We simulate the real-time dynamics of a massive Schwinger model using the Time-Evolving Block Decimation tensor network algorithm. Starting from a non-equilibrium initial state with localized energy excitation on top of vacuum, we track the subsequent evolution to investigate two distinct physical phenomena. First, by analyzing the system's energy-momentum tensor, we show that this system exhibits hydrodynamic behavior analogous to Bjorken flow at large coupling-to-mass ratio, a signature that diminishes as the coupling weakens, or mass increases. Second, by examining the evolution of the electric field and charge density, we observe the signal of spontaneous parity symmetry breaking phase transition in a dynamical system. The parity-restored regime is marked by ''string breaking'' and efficient charge screening, while the parity-broken regime displays stable propagation of nearly free charges and persistent electric fields connecting them.

   hep-phhep-latnucl-th5 citations
4. 04*

   Onset of Bjorken Flow in Quantum Evolution of the Massive Schwinger Model

   Haiyang Shao🇨🇳 · Shile Chen🇨🇳 · Shuzhe Shi🇨🇳

   The onset of hydrodynamics in the hot medium created in relativistic heavy-ion collisions is a crucial theoretical question. A first-principle simulation requires a real-time, non-perturbative calculation of the quantum system. In this Letter, we perform such simulations using the tensor network method, which enables large-scale quantum many-body simulations by retaining only the most essential quantum states for collective behaviors. We focus on the massive Schwinger model, a low-dimensional analog of quantum chromodynamics (QCD), as they share important properties such as confinement and chiral symmetry breaking. Starting from an initial state that puts a localized excitation atop the vacuum and mimics the energy deposition from colliding nuclei, we observe hydrodynamic behavior consistent with Bjorken flow in all relevant degrees of freedom: energy density, fluid velocity, and bulk pressure. The time scale for hydrodynamic onset aligns with the thermalization time of the quantum distribution function.

   hep-phhep-latnucl-th9 citations
5. 05*

   Exploring the Null Results in the Direct Detection Experiments, $(g-2{)}_{\ell }$ and Neutrino Mass in an Extended $U(1{)}_{L_{\mu }-L_{\tau }}$ Model Constrained through the $Z\to {\ell }^{+}{\ell }^{-}$ Decays

   Bibhabasu De🇮🇳

   The Direct Detection~(DD) experiments are vital for probing the particle nature of Dark Matter~(DM). However, in the absence of a scattering event, DD searches result in stringent bounds on the corresponding parameter space. The paper has considered a $U(1{)}_{L_{\mu }-L_{\tau }}$-extension of the Standard Model~(SM) and augmented the particle spectrum with $SU(2{)}_L$-singlet vector-like leptons and scalars. A discrete $Z_2$ symmetry stabilizes the lightest SM-singlet vector-like lepton as the viable DM candidate. In the proposed model, amplitude-level cancellation can be achieved for both DM-electron and DM-quark scatterings, leading to a trivial explanation for the continuous null results in the DD experiments. The framework can also induce one-loop corrections to the lepton anomalous magnetic moments and $Z{\ell }^{+}{\ell }^{-}$ couplings. The experimental bounds on the $Z\to {\ell }^{+}{\ell }^{-}$ decays are instrumental in constraining the model parameters. Particularly, using the $Z\to {\tau }^{+}{\tau }^{-}$ decay, a stronger exclusion limit can be imposed on the $U(1{)}_{L_{\mu }-L_{\tau }}$ parameter space. Further, in the presence of three heavy right-handed neutrinos, transforming as $Z_2$-even states, the model can explain all the neutrino mass and mixing constraints using the Type-I seesaw mechanism. Future experimental updates on the $(g-2{)}_{\ell }$, $Z\to {\ell }^{+}{\ell }^{-}$ decays and improved bounds on the $U(1{)}_{L_{\mu }-L_{\tau }}$ theory can be crucial to test the proposed model. Moreover, future DD experiments searching for a DM-muon scattering might be significant to probe the considered DM-SM interaction.

   hep-phhep-exJHEP(2025)·4 citations
6. 06*

   Heavy tetraquarks in the hyperspherical approach

   F. A. Martynenko🇷🇺 · A. V. Eskin🇷🇺 · A. P. Martynenko🇷🇺

   Within the quark model and hyperspherical method, the bound states of four heavy quarks and antiquarks (tetraquarks) are investigated. In hyperradial approximation, the Schroedinger equation is reduced to a one-dimensional equation after averaging over angles in hyperspace. This equation is solved numerically and analytically within the variational method. The hyperfine structure of the spectrum is calculated. To increase the accuracy of the calculation, corrections to the energy levels from the QCD generalization of the Breit Hamiltonian are taken into account.

   hep-phNPA(2026)·2 citations
7. 07*

   Relations of meson and nucleon electromagnetic and gravitational radii with quarks and gluons contributions

   O.V. Selyugin🇷🇺 · O.V. Teryaev🇷🇺

   The electromagnetic and gravitational form factors of the nucleon determined by quark and gluon contributions are calculated using the momentum transfer dependence of generalized parton distributions with different forms of parton distribution functions obtained by various Collaborations. The power forms of gravitational form factors of quarks and gluons are examined. It is shown that the gluon gravitational radius of the nucleon is comparable to the electromagnetic radius of the proton; however, the quark gravitational radius of the nucleon is less than its electromagnetic radius. It is shown that the gluon gravitational form factor drops faster than the quark gravitational form factor at large transfer momenta and corresponds to the triple form.

   hep-phhep-exMoscow Univ.Phys.Bull.(2025)·0 citations
8. 08*

   Symmetric tensor portals to dark matter I: Creation of dark scalars

   Brian Dignean🇨🇦 · Alexander J. Magnus🇨🇦 · Rainer Dick🇨🇦

   We examine the creation of scalar dark matter through a symmetric tensor portal. We find that both freeze-in and thermal freeze-out through a symmetric tensor mediator can create scalar dark matter. The required tensor masses for freeze-in are much larger than for freeze-out for the same dark-matter mass, in agreement with the nonthermalization assumption in freeze-in scenarios.

   hep-phhep-thJ.Subatomic Part.Cosmol.(2025)·1 citation
9. 09*

   Sign-Flipping Axion Potentials via Kapitza-Type Modulation by Heavy Axions

   Kai Murai🇯🇵 · Fuminobu Takahashi🇯🇵 · Kosei Tomiyama🇯🇵

   We show that the potential of a light axion can flip sign, or even nearly vanish, as a result of coherent oscillations of a heavier axion with which it mixes. This phenomenon is analogous to the Kapitza pendulum, where a high-frequency external force stabilizes an otherwise unstable configuration, but here it arises naturally from the inherent mass hierarchy and mixing among axions in the axiverse, without the need for any externally imposed modulation. We further show that a late-time sign flip of the potential can significantly enhance the abundance of the light axion, which has important cosmological and observational consequences.

   hep-phastro-ph.COJHEP(2026)·5 citations
10. 10*

    Focused Angular $N$-Body Event Generator (FANG)

    Itay Horin🇮🇱 · Arik Kreisel🇮🇱 · Or Alon🇮🇱

    We introduce FANG (Focused Angular $N$-body event Generator), a new Monte Carlo tool for efficient event generation in restricted Lorentz-Invariant Phase Space (LIPS). Unlike conventional approaches that sample the full $4\pi$ solid angle, FANG directly generates events in which selected final-state particles are constrained to fixed directions or finite angular regions in the laboratory frame. Because of the way the generator is constructed, angular constraints can be imposed directly in the laboratory frame while maintaining the correct LIPS structure, enabling differential and total cross sections or decay rates to be computed with high efficiency. The method is validated against analytic results and existing event generators, showing excellent agreement. By reducing the computational cost of full phase-space event generation by several orders of magnitude, FANG provides a robust and versatile framework applicable to particle, nuclear, and detector physics.

    hep-phJHEP(2025)·1 citation
11. 11*

    Gravitational Waves from $\text{Type-I}$ Strings in a Neutrino Mass Model

    Adeela Afzal🇷🇺

    In this work, we propose a novel realization of $\text{type-I}$ cosmic strings arising from the spontaneous breaking of an extended gauge symmetry $SU(2{)}_R\times U(1{)}_{B-L}$ in the context of a low-scale split seesaw mechanism for neutrino mass generation. We demonstrate that the split seesaw framework, which explains the smallness of neutrino masses, naturally motivates a small scalar self-coupling $\lambda$. This intrinsically links the neutrino mass generation mechanism to the formation of $\text{type-I}$ cosmic strings, where the gauge coupling dominates over the scalar self-coupling ($\beta \equiv \lambda /2g^2<1$). We explore the cosmological implications of these strings, including their gravitational wave signatures that are testable in current and future experiments. Our findings establish a compelling and testable connection between neutrino mass generation and cosmic string phenomenology in an underexplored region of parameter space.

    hep-phastro-ph.COhep-thPhys.Dark Univ.(2026)·2 citations
12. 12*

    Investigating the two-pion exchange of the double charm $D{D}^{\ast }$ chiral interactions and $T_{cc}$

    Hao Xu🇨🇳 · Li-xiang Ren🇨🇳

    Under chiral effective field theory, we study the $S$-wave $D{D}^{\ast }$ interactions up to second chiral order at one-loop level, which contain full contact, one-pion-exchange (OPE) and two-pion-exchange (TPE) contributions. Here, we adopt a new subtraction scheme of the two-particle-reducible contributions, and attempt different regularization schemes uniquely for the TPE contributions since they are highly divergent on the momentum transfer. Under these schemes we conclude that, in the $I=0$ channel, the TPE contribution is repulsive, then the competition between this powerful repulsing TPE and the other two (contact and OPE) results in a quite weak attraction. This explains why $T_{cc}$ has an extremely small binding energy if treated as the $I=0$ $D{D}^{\ast }$ bound state. This feature resembles that of hidden charm $D{\bar{D}}^{\ast }$ as we investigated in previous work [Phys. Rev. D 105, 034013 (2022)], which also interpreted the extremely near-threshold phenomenon of $X(3872)$. In addition, we also solve the Bethe-Salpeter equation with the chiral interactions for a consistency check.

    hep-phPRD(2025)·2 citations
13. 13*

    Roper resonance $N^{\ast }(1440)$ from charmonium decays

    Bing-Song Zou🇨🇳

    The Roper resonance $N^{\ast }(1440)$ was discovered by David Roper in 1964 through sophisticated partial-wave analyses of $\pi N$ scattering data. However the first direct observation of the Roper resonance peak in the $\pi N$ invariant mass spectrum was only realized 40 years later from the charmonium decay $J/\psi \to \bar{p}n{\pi }^{+}+c.c.$ at Beijing Electron-Positron Collider. The further observations of the Roper resonance production from various charmonium decays helped to reveal its multiquark nature with large $\sigma N$ component.

    hep-phActa Phys.Polon.B(2026)·2 citations
14. 14*

    Diffractive vector meson photo-production in oxygen-oxygen and neon-neon ultraperipheral collisions at energies available at the CERN Large Hadron Collider

    J. Cepila🇨🇿 · J. G. Contreras🇨🇿 · M. Matas🇨🇿 · A. Ridzikova🇨🇿

    The energy-dependent hotspot model is used to predict cross sections for vector-meson diffractive photo-nuclear production off oxygen ($\gamma$O) and neon ($\gamma$Ne) that can be extracted from ultra-peripheral O--O and Ne--Ne collisions, recently recorded at the LHC. In both cases, two models are used to describe the nuclear shapes. Woods-Saxon prescriptions for O and Ne as well as an alpha-cluster description of O and a bowling-pin-like shape for Ne, according to the PGCM formalism. Predictions are presented for the dependence on the centre-of-mass energy of the photon--nucleus system, as well as on Mandelstam-$t$, of the cross sections for the coherent and the incoherent photo-nuclear production of ${\rho }^0$ and J/$\psi$ vector mesons. Furthermore, the rapidity dependence of the ultra-peripheral cross section is reported for all cases. It is found that the incoherent process provides a measurable signature for the approach to the gluon-saturation regime, and that the simultaneous determination of ${\rho }^0$ and J/$\psi$ coherent and incoherent production provides a strong constraint on nuclear models for both O and Ne.

    hep-phnucl-thPRC(2026)·2 citations
15. 15*

    First determination of $V_{cs,cd}$ from inclusive $D$ meson decays

    Kang-Kang Shao🇨🇳 · Hai-Long Feng🇨🇳 · Xue-Yin Liu🇨🇳 · Qin Qin🇨🇳 · Liang Sun🇨🇳 · Fu-Sheng Yu🇨🇳

    We report the first determination of the Cabibbo-Kobayashi-Maskawa matrix elements $|V_{cs}|$ and $|V_{cd}|$ from a global fit to data from inclusive and sum-of-exclusive charm decays. Simultaneously, the heavy quark expansion parameters are determined, and they are in good agreement with results from the literature, validating the robustness of this work. With the current precision, our determined value for $|V_{cs}|$ is consistent with the world-average value extracted from exclusive charm decay processes, while a tension of approximately $3\sigma$ is observed for $|V_{cd}|$ when compared to its exclusive world-average counterpart.

    hep-phhep-ex4 citations
16. 16*

    Experimental Uncertainty Propagation in Neural Network Extraction in Hadronic Physics

    Dustin Keller🇺🇸

    Obtaining Compton Form Factors (CFFs) and Transverse Momentum Dependent parton distribution functions (TMDs) from experimental data using neural network-based information extraction requires the precise propagation of experimental errors. Accurate representation of uncertainties and detailed experimental covariance matrices, accounting for both statistical and systematic uncertainties, are essential for high-quality extractions. This paper explores instrumental and analytical contributions to fit and model uncertainties, along with methods for integrating these uncertainties into quantifiable results, ensuring robust extraction of physical observables across local and global datasets. Using pseudodata we demonstrate the critical role of accurate uncertainty propagation in producing meaningful results and advancing our understanding of partonic structure and dynamics inside of hardrons. \keywords{Deep neural networks \and Hadronic Physics \and Transverse momentum dependent parton distributions functions \and Compton form factors \and Uncertainty Analysis

    hep-ph4 citations
17. 17*

    One-loop QCD corrections to SSA in unweighted Drell-Yan processes

    Guang-Peng Zhang🇨🇳

    We study one-loop QCD corrections to the single transverse spin asymmetry in Drell-Yan process. The invariant mass of virtual photon and angular distributions of final lepton in Collins-Soper frame are measured. Especially, the transverse momentum of virtual photon is integrated out. Collinear twist-3 factorization formalism is adopted for the asymmetry. We use Feynman gauge in this work. To eliminate dependent twist-3 distribution functions, equation of motion for quark is used. The results satisfy both QED and QCD gauge invariance. It is confirmed that all divergences from virtual and real corrections can be removed consistently by collinear subtraction. Finite hard coefficients for the convolution of $\bar{q}(x)$ and $T_F(x_1,x_2)$ are presented.

    hep-phJHEP(2026)·1 citation
18. 18*

    Geometric representation of CP phases ${\delta }_{\mathrm{PDG}},{\delta }_{\mathrm{KM}}$ in flavor mixing matrix and its sum rule by alternative unitarity triangle and quadrangle

    Masaki J. S. Yang🇯🇵

    In this letter, we present a geometric representation of the CP phases ${\delta }_{\mathrm{PDG}}$ and ${\delta }_{\mathrm{KM}}$ in the PDG and Kobayashi--Maskawa parameterizations of the flavor mixing matrix in the complex plane. The sum rule with the unitarity triangle ${\delta }_{\mathrm{PDG}}+{\delta }_{\mathrm{KM}}=\pi -\alpha +\gamma$ is expressed as a quadrangle, which is a combination of a unitarity triangle and an alternative triangle. Through the unitarity quadrangle, the CP phases are also identified with specific geometric angles. Furthermore, a new set of inverse unitarity triangles is defined from the inversion formula of a unitary matrix $U^{†}=U^{-1}$. These novel triangles contain standard angles of the form $\arg [U_{\alpha i}{U}_{\beta j}{U}_{\alpha j}^{\ast }{U}_{\beta i}^{\ast }]$ and new angles $\arg [U_{\alpha i}{U}_{\beta j}{U}_{\gamma k}/\det U]$, which directly determine nontrivial arguments of the mixing matrix elements.

    hep-phPLB(2026)·8 citations
19. 19*

    Double Deeply Virtual Compton Scattering as a probe of Generalized Parton Distributions

    J. S. Alvarado🇫🇷 · M. Hoballah🇫🇷 · E. Voutier🇫🇷

    Generalized Parton Distributions (GPDs) are multidimensional structure functions of hadrons, encoding mechanical and spin properties through the correlation of the momentum and transverse position of partons. While channels like Deeply Virtual Compton Scattering (DVCS) access GPDs in a constrained kinematic domain, Double Deeply Virtual Compton Scattering (DDVCS) offers broader access to the GPD phase space, though it remains unmeasured. We present a feasibility study of DDVCS observables using polarized electron beams at Jefferson Lab and the EIC, focusing on their sensitivity to helicity-conserving GPDs and implications for Compton Form Factor (CFF) extraction. Moreover, we provide experimental projections supporting the feasibility of the measurements at both facilities.

    hep-phEPJ Web Conf.(2026)·0 citations
20. 20*

    Deciphering the nature of $X(2300)$ with the PACIAE model

    Jian Cao🇨🇳 · Wen-Chao Zhang🇨🇳 · Jin-Peng Zhang🇨🇳 · Bo Feng🇨🇳 · An-Ke Lei🇨🇳 · Zhi-Lei She🇨🇳 · Hua Zheng🇨🇳 · Dai-Mei Zhou🇨🇳 · Yu-Liang Yan🇨🇳 · Ben-Hao Sa🇨🇳

    Inspired by the BESIII newest observation of an axial-vector particle $X(2300)$ in the $\psi (3686)\to \varphi \eta {\eta }^{\prime }$ process, we simulate its production in $e^{+}{e}^{-}$ collisions at $\sqrt{s}=4.95$ GeV using the parton and hadron cascade model PACIAE 4.0. In this model, the final partonic state (FPS) and hadronic state (FHS) are simulated and recorded sequentially. We propose, for the first time, that $X(2300)$ could be a $q\bar{q}s\bar{s}$ ($q=u/d$) state or a hadro-strangeonium state, i.e., a bound system of a strangeonium and a light hadron. The excited strangeonium candidate is formed by coalescing an $s\bar{s}$ quark pair in the FPS with the quantum statistical mechanics inspired dynamically constrained phase-space coalescence model. The tetraquark candidates of $q\bar{q}s\bar{s}$ and $ss\bar{s}\bar{s}$ are similarly produced by coalescing four constituent quarks in the FPS. In contrast, a hadro-strangeonium candidate emerges from the recombination of the constituent $\varphi$ and $\eta /\eta$ in the FHS. We then calculate the $X(2300)$'s orbital angular momentum quantum number in its rest frame and perform the spectral classification for each of the above candidates. Given its quantum numbers $J^{PC}=1^{+-}$, $X(2300)$ is identified as a $P$-wave $s\bar{s}$, an $S$-wave $q\bar{q}s\bar{s}/ss\bar{s}\bar{s}$ or $S$-wave $\varphi {\eta }^{\prime }/\varphi \eta$ candidate. For the first time, we estimate the production rates for these configurations. The $P$-wave $s\bar{s}$ and $S$-wave $q\bar{q}s\bar{s}$ states are produced at rates on the order of $10^{-5}$, whereas the $S$-wave $ss\bar{s}\bar{s}$ and $\varphi {\eta }^{\prime }/\varphi \eta$ states appear at rates on the order of $10^{-6}$. Moreover, significant discrepancies are observed in the rapidity and transverse momentum distributions among different candidates. These discrepancies could be served as valuable criteria for deciphering the nature of $X(2300)$.

    hep-phhep-thPRD(2026)·4 citations
21. 21*

    Enabling stable preservation of ML algorithms in high-energy physics with petrifyML

    Andy Buckley🇬🇧 · Louie Corpe🇫🇷 · Martin Habedank🇬🇧 · Tomasz Procter🇵🇱

    Machine learning (ML) in high-energy physics (HEP) has moved in the LHC era from an internal detail of experiment software, to an unavoidable public component of many physics data analyses. Scientific reproducibility thus requires that it be possible to accurately and stably preserve the behaviours of these, sometimes very complex algorithms. We present and document the petrifyML package, which provides missing mechanisms to convert configurations from commonly used HEP ML tools to either the industry-standard ONNX format or to native Python or C++ code, enabling future re-use and re-interpretation of many ML-based experimental studies.

    hep-phhep-exSciPost Phys. Codebases 78 (2026)·5 citations
22. 22*

    Extraction of Dihadron Fragmentation Functions at NNLO with and without Neural Networks

    Virgile Mahaut🇫🇷 · Luca Polano🇮🇹 · Alessandro Bacchetta🇮🇹 · Valerio Bertone🇫🇷 · Matteo Cerutti🇫🇷 · Marco Radici🇮🇹 · Lorenzo Rossi🇮🇹

    We present a new extraction of unpolarized Dihadron Fragmentation Functions, which describe the probability density for an unpolarized parton to fragment into a ${\pi }^{+}{\pi }^{-}$ pair. Our analysis is based on data from the BELLE collaboration. We improve on previous determinations in several key aspects: we employ state-of-the-art perturbative QCD calculations up to next-to-next-to-leading order (NNLO); we limit the use of Monte Carlo event generators to estimating the relative contributions of different flavors, a necessary input due to the limited flavor sensitivity of the available data; and, in addition to a traditional fit based on a physics-informed functional form, we explore a Neural Network parametrization. This latter approach paves the way for more robust and flexible determinations of Dihadron Fragmentation Functions using machine learning techniques.

    hep-phJHEP(2026)·6 citations
23. 23*

    Enhanced Cosmic-Ray Cooling in AGN from Dark Matter Deep Inelastic Scattering

    Linjie Li🇨🇳 · Chih-Ting Lu🇨🇳 · Arvind Kumar Mishra🇨🇳 · Liangliang Su🇨🇳 · Lei Wu🇨🇳

    The diffusion of high-energy cosmic rays (CRs) through the dark matter (DM) spikes of active galactic nuclei entails significant energy loss via interactions with DM. While previous studies of sub-GeV DM have focused on elastic scattering, this process becomes insufficient at higher proton energies and DM masses. In this work, we investigate the CR-DM deep inelastic scattering (DIS) as mediated by a vector portal. We calculate the DIS contribution to the CR energy loss rate and derive stringent exclusion limits on the CR-DM scattering cross-section for DM masses between $10^{-6}$ GeV and $1$ GeV. For higher CR energies and mediator masses, the resulting CR cooling timescales are reduced by orders of magnitude after involving the DIS contribution, producing stringent constraints that surpass most of current experimental limits.

    hep-ph6 citations
24. 24*

    Dark Parton Shower Effects for Cosmic Ray Boosted Dark Matter

    Zirong Chen🇨🇳 · Shao-Feng Ge🇨🇳 · Jinmian Li🇨🇳 · Junle Pei🇨🇳 · Feng Yang🇨🇳 · Cong Zhang🇩🇪

    We investigate the dark parton shower effects in the direct detection of cosmic-ray boosted dark matter (CRDM), focusing on a dark photon-mediated model with fermionic dark matter-electron interactions. Utilizing a Monte Carlo framework to incorporate the Sudakov form factors and kinematic dipole recoil schemes, we simulate the CRDM energy spectrum evolution under the dark sector splitting. Our results reveal a significant energy-dependent modification of the CRDM flux. For a 1 keV dark matter (DM) mass and a coupling of $g_D=3$, the CRDM flux can be enhanced by a factor up to 1.12 in the $\mathcal{O}(10^{-2}\sim 1)$ MeV energy range for $2m_{\chi }\lesssim m_{A^{\prime }}\lesssim 10^{-2}$ MeV, while it is suppressed by more than $50\%$ at energy around 100 MeV for $m_{A^{\prime }}\lesssim 10^{-3}$ MeV. We then translate these effects into the experimental sensitivities for PandaX-4T, Super-Kamiokande, and JUNO. At $m_{A^{\prime }}=10^{-3}$ MeV and $g_D=3$, the bounds on the kinetic mixing parameter ${ϵ}^2$ are relaxed by factors of 1.02, 1.6 and 1.4, respectively. Finally, we demonstrate that the parameter space considered is consistent with those astrophysical constraints on dark matter self-interactions from observations of the Bullet Cluster.

    hep-phhep-ex2 citations
25. 25*

    Discovering the $D_0^{\ast }(2100)$ in $B$ semileptonic decays

    M.-L. Du🇨🇳 · F.-K. Guo🇨🇳 · C. Hanhart🇩🇪 · F. Herren🇨🇭 · B. Kubis🇩🇪 · R. van Tonder🇩🇪

    The mass and width of the lightest scalar open-charm state listed in the Review of Particle Physics, the $D_0^{\ast }(2300)$, are in puzzling tension with predictions from unitarized chiral perturbation theory (UChPT) and lattice QCD, which favor a lighter state at around $2100$ MeV. However, to date, no direct experimental evidence for this lighter state exists. In an effort to facilitate a direct observation, we introduce angular asymmetries of $B\to D\pi \ell \nu$ decays that allow for a direct extraction of the $D\pi$ S-wave phase shift and discuss a novel measurement strategy for the Belle II experiment. We conduct a sensitivity study, finding that the Belle II experiment can determine the pole location with sufficient precision to firmly establish the $D_0^{\ast }(2100)$ using the currently available data set. We also investigate the possibility and necessary statistics of measuring the $D\pi$ isospin 1/2 scattering length with an accuracy sufficient to distinguish between the predictions from both UChPT and lattice QCD and the measurement by ALICE using femtoscopy.

    hep-phhep-exhep-latEPJC(2025)·8 citations
26. 26*

    New constraints on $Z^{\prime }$ from captured dark matter annihilation in astrophysical objects

    Basabendu Barman🇮🇳 · Pooja Bhattacharjee🇸🇮 · Arindam Das🇯🇵

    Considering dark matter capture in astrophysical objects such as neutron stars and brown dwarfs, followed by their annihilation into two neutrino and four neutrino final states, we derive new constraints on the mass and coupling of a novel abelian gauge boson $Z^{\prime }$ arising from an anomaly-free $U(1)$ extension of the Standard Model. We further confront these astrophysical limits with complementary bounds from the Planck-observed relic abundance via the freeze-in mechanism, big bang nucleosynthesis (BBN), gravitational wave signatures from cosmic strings, and searches at energy and intensity frontier experiments.

    hep-phastro-ph.HEhep-ex1 citation
27. 27*

    Taming the dark photon production via a non-minimal coupling to gravity

    Oleg Lebedev🇫🇮 · Jong-Hyun Yoon🇰🇷

    Inflationary production of massive dark photons with non-minimal couplings to gravity shows surprising growth at large momenta. These couplings appear in the effective low energy description of a more fundamental theory. We find that the growth is absent in explicit gauge invariant UV-complete models. Such completions are also free of "ghost" instabilities, which often appear in the effective models.

    hep-phastro-ph.COgr-qchep-thPLB(2026)·3 citations
28. 28*

    Towards a theory of dissipative Dark Matter I: the Born limit

    Garance Lankester--Broche🇦🇹 · Josef Pradler🇦🇹

    We derive the energy-differential cross section and energy loss rate for dissipative self-interacting dark matter (dSIDM) models within the Born regime using perturbative quantum field theory. Six dissipative scenarios are considered, incorporating the emission of particles that may be either massless or possess a kinematically allowed light mass. Both short-range and long-range force-mediated dSIDM interactions are examined. In the non-relativistic regime, we obtain closed-form expressions of the energy-differential cross sections by a controlled expansion in the initial relative dark matter velocity. Up to trivial factors, the leading-order squared emission amplitude is model-independent for massless emissions. Model dependence arises for massive particle emission and at the next-to-leading order. The latter reduces to three distinct cases. The derived analytical expressions exhibit excellent agreement with numerical computations, providing simple, ready-to-use formulas. Furthermore, we analyze the behavior of these processes in the soft emission limit. Our results show that additional corrections are necessary when applying factorization at the next-to-leading order in a velocity expansion to ensure consistency between the soft energy-differential cross section and the full counterparts across a broad energy range. Finally, we investigate the regime of perturbative validity in terms of the model parameters, identifying the conditions under which our results are applicable.

    hep-phJCAP(2026)·2 citations
29. 29*

    $D_N$-Orthogonal Freedom in the Canonical Seesaw: Flavor Invariants and Physical Non-Equivalence of F-Classes

    Jianlong Lu🇸🇬

    We study basis-independent structures in the Type-I seesaw mechanism for light Majorana neutrinos, assuming the canonical scenario with three heavy right-handed (sterile) neutrinos. Let $m_{\nu }$ denote the $3\times 3$ mass matrix of light neutrinos, obtained at tree level from heavy Majorana singlets with diagonal mass matrix $D_N=\mathrm{diag}(M_1,M_2,M_3)$ and Dirac matrix $m_D$. We show that all right-actions $F$ on the seesaw matrix that leave $m_{\nu }$ unchanged form the group $G=D_N^{1/2}O(3,\mathbb{C})D_N^{-1/2}$. While oscillation data determine the PMNS matrix $U_{\mathrm{PMNS}}$ and the mass-squared splittings, they do not fix the $F$-class within $G$. We classify basis-invariant quantities into those that are class-blind (e.g.\ $\det \eta$) and class-sensitive (e.g. $\mathrm{Tr}\eta$, $\mathrm{Tr}{\eta }^2$, an alignment measure, and CP-odd traces relevant to leptogenesis), where $\eta$ denotes the non-unitarity matrix of the light sector. We provide explicit formulas and both high-scale and GeV-scale benchmark examples that illustrate these invariant fingerprints and their scaling with $D_N$. This converts the degeneracy at fixed $m_{\nu }$ into measurable, basis-invariant fingerprints.

    hep-phUniverse(2025)·2 citations
30. 30*

    Renormalization Group Approach to Confinement

    Gerrit Schierholz🇩🇪

    While we have several complementary models of confinement, some of which are phenomenologically appealing, we do not have the ability to calculate analytically even simple aspects of confinement, let alone have a framework to eventually prove confinement. The problem we are facing is to evolve the theory from the perturbative regime to the long distance confining regime. This is generally achieved by renormalization group transformations. With the gradient flow we now have a technique to address the problem from first principles. The primary focus is on the running coupling ${\alpha }_S(\mu )$, from which confinement can be concluded alone. A central point is that the gluon condensate is scale invariant, which reflects its self-similar behavior across different scales. Building on that, we derive ${\alpha }_S(\mu )\simeq {\Lambda }_S^2/{\mu }^2$, which evolves to the infrared fixed point $1/{\alpha }_S=0$ in accordance with infrared slavery. The only important factor appears to be the presence of the gluon condensate, which is a universal feature that QCD shares with many other models. The analytical results are supported by numerical simulations.

    ↳ hep-lathep-phhep-thnucl-thEPJC(2026)·1 citation
31. 31*

    Probing For Non-Gravitational Long-Range Dark Matter Interactions

    M.P. Ross🇺🇸 · S.K. Apple🇺🇸 · E.A. Shaw🇺🇸 · C. Gettings🇺🇸 · I.A. Paulson🇺🇸 · J.H. Gundlach🇺🇸

    Dark matter remains a mystery in fundamental physics. The only evidence for dark matter's existence is from gravitational interactions. We constructed a precision torsion balance experiment to search for non-gravitational, long-range interactions between ordinary matter in our lab and the Milky Way's dark matter. We find no evidence of such interaction and set strict upper bounds on its strength. These results suggest that dark matter only interacts gravitationally over long distances and constrains a variety of dark matter theories.

    ↳ gr-qchep-exhep-ph2 citations
32. 32*

    Measuring neutrino masses with joint JWST and DESI DR2 data

    Sheng-Han Zhou🇺🇸 · Tian-Nuo Li🇺🇸 · Guo-Hong Du🇺🇸 · Jun-Qian Jiang🇨🇳 · Jing-Fei Zhang🇺🇸 · Xin Zhang🇺🇸

    Early JWST observations reveal an unexpectedly abundant population of high-redshift candidate massive galaxies at $z\gtrsim 7$, and recent DESI measurements show a preference for dynamical dark energy, which together present a significant challenge to the standard $\Lambda$CDM cosmology. In this work, we jointly analyze high-redshift galaxy data from JWST, baryon acoustic oscillations data from DESI DR2, and cosmic microwave background (CMB) data from Planck and ACT, measuring the total neutrino mass $\sum m_{\nu }$. We consider three dark energy models ($\Lambda$CDM, $w$CDM, and $w_0{w}_a$CDM) and three mass hierarchies. Our results indicate that in the $w_0{w}_a$CDM model, adding JWST data to CMB+DESI tightens the upper limit of $\sum m_{\nu }$ by about $5.8\%-10.2\%$, and we obtain $\sum m_{\nu }<0.167\mathrm{eV}$ ($2\sigma$) in the normal hierarchy (NH) case. Furthermore, JWST also offers indicative lower limits on star formation efficiency parameter of $f_{\ast ,10}\gtrsim 0.146-0.161$. Bayesian evidence weakly favors the $w_0{w}_a$CDM+$\sum m_{\nu }$(NH) model relative to the $\Lambda$CDM+$\sum m_{\nu }$(NH) model using CMB+DESI+JWST data. These results suggest that the joint analysis of high-redshift JWST data and low-redshift DESI data provides compelling constraints on neutrino mass and merits further investigation.

    ↳ astro-ph.COgr-qchep-phPRD(2025)·31 citations
33. 33*

    A Dark Matter Model with Quadratic Equation of State: Background Evolution and Structure Formation

    Kazem Rezazadeh🇮🇷 · Ebrahim Yusofi🇮🇷 · Alireza Talebian🇮🇷

    We propose that dark matter (DM) possesses a quadratic equation of state, which becomes significant at high densities, altering the Universe's evolution during its early stages. We derive the modified background evolution equations for the Hubble parameter $H(z)$ and the DM density parameter ${\Omega }_{\text{dm}}(z)$. We then perturb the governing equations to study the linear growth of matter fluctuations, computing the observable growth factor $f{\sigma }_8(z)$. Finally, we compare the model with the latest cosmological data, including Hubble parameter $H(z)$ measurements, and growth factor $f{\sigma }_8(z)$ data, up to $z=3$. Our results indicate that the quadratic model, while remaining consistent with background observations, offers a distinct imprint on the growth of structure, providing not only a new phenomenological avenue to address cosmological tensions but also shedding light on the nature of DM.

    ↳ astro-ph.COastro-ph.GAgr-qchep-phAstrophysics(2025)·17 citations
34. 34*

    Dual is Different: EFTs, Axions and Nonpropagating Form Fields in Cosmology

    C.P. Burgess🇨🇦 · F. Quevedo🇬🇧

    Scalar fields in 4D are known to have equivalent dual descriptions in terms of form-field gauge potentials, but this is often regarded as an arcane fact. Why use more complicated formulations when simpler scalar descriptions exist and are equivalent? We describe three ways in which scalars that arise as duals can differ from their garden-variety counterparts. Two of these -- the interchange of weak and strong couplings and utility in bringing topological information to the low-energy theory -- are relatively well-known, but to these we add a third: dualities that map derivative interactions to non-derivative interactions seem not to commute with the general power-counting arguments that quantify control over the low-energy approximation within any EFT involving gravity. Since both sides of the duality must agree on their low-energy limit, the non-derivative interactions on the scalar side of the duality turn out to be suppressed relative to what would generically be assumed. They are nonetheless technically natural, as is particularly clear in the dual formulation. We argue that scalar fields arising as duals (such as the universal axion $a$ from string vacua) that have the commonly assumed $J^{\mu }{\partial }_{\mu }a$ interaction with matter also have $J^{\mu }{J}_{\mu }$ contact interactions among the respective currents, some of whose implications we explore. We also emphasize the non-trivial role and cosmological implications of non-propagating 3-form gauge potentials and clarify confusing statements recently made in the literature regarding the validity of duality for massive form fields.

    ↳ hep-thgr-qchep-ph8 citations
35. 35*

    QCD Effective Lagrangian and Condensation of Chromomagnetic Flux Tubes

    George Savvidy🇬🇷

    We compute the effective action for covariantly constant gauge fields that are solutions of the sourceless Yang-Mills equation and have the form of magnetic flux tubes. They represent a superposition of infinite many alternating monopole/ani-monopole pairs situated at infinity, with each pair having a structure similar to the Nielsen-Olesen magnetic flux tube. The chromomagnetic flux tubes condensation is stable and indicates that the Yang-Mills vacuum state is highly degenerate.

    ↳ hep-thhep-phEPJC(2026)·1 citation
36. 36*

    Observation of quantum-field-theory dynamics on a spin-phonon quantum computer

    Anton T. Than🇺🇸 · Saurabh V. Kadam🇺🇸 · Vinay Vikramaditya🇺🇸 · Nhung H. Nguyen🇺🇸 · Xingxin Liu🇺🇸 · Zohreh Davoudi🇺🇸 · Alaina M. Green🇺🇸 · Norbert M. Linke🇺🇸

    Simulating out-of-equilibrium dynamics of quantum field theories in nature is challenging with classical methods, but is a promising application for quantum computers. Unfortunately, simulating interacting bosonic fields involves a high boson-to-qubit encoding overhead. Furthermore, when mapping to qubits, the infinite-dimensional Hilbert space of bosons is necessarily truncated, with truncation errors that grow with energy and time. A qubit-based quantum computer, augmented with an active bosonic register, and with qubit, bosonic, and mixed qubit-boson quantum gates, offers a more powerful platform for simulating bosonic theories. We demonstrate this capability experimentally in a hybrid analog-digital trapped-ion quantum computer, where qubits are encoded in the internal states of the ions, and the bosons in the ions' motional states. Specifically, we simulate nonequilibrium dynamics of a (1+1)-dimensional Yukawa model, a simplified model of interacting nucleons and pions, and measure fermion- and boson-occupation-state probabilities. These dynamics populate high bosonic-field excitations starting from an empty state, and the experimental results capture well such high-occupation states. This simulation approaches the regime where classical methods become challenging, bypasses the need for a large qubit overhead, and removes truncation errors. Our results, therefore, open the way to achieving demonstrable quantum advantage in qubit-boson quantum computing.

    ↳ quant-phcond-mat.quant-gashep-lathep-ph+114 citations
37. 37*

    $A_{\beta }[E_{\beta }]$ in ${}^{37}$K decay: new physics with opposite $\beta$ helicity

    Melissa Anholm🇨🇦 · J.A. Behr🇨🇦 · D.G. Melconian🇺🇸 · G. Gwinner🇨🇦 · A. Gorelov🇨🇦 · J.C. McNeil🇨🇦 · B. Fenker🇺🇸 · S. Behling🇺🇸

    By extending our analysis and simulations of our ${}^{37}$K $\beta$-decay data set to allow the $\beta$ asymmetry with respect to nuclear spin to vary with $\beta$ energy $E_{\beta }$, we have gained sensitivity to new physics that depends on a helicity factor for the $\beta$, $m_{\beta }/E_{\beta }$. In particular, we constrain Lorentz scalar and tensor quark-lepton interaction strengths at a sensitivity complementary to the similar Fierz interference term in neutron $\beta$ decay. Our result for that new physics is a Fierz interference term $b$ = 0.033 $\pm$ 0.084 (stat) $\pm$ 0.039 (syst), consistent with the standard model electroweak interaction value $b=0$. We consider presently achieved complementarity to $\beta$-decay and particle physics experiments, along with projectable technical improvements to our method.

    ↳ nucl-exhep-phnucl-thPRC(2026)·0 citations
38. 38*

    Gravitational Signatures of Axion Dark Matter via Parity-Violating Interactions

    Marco Figliolia🇮🇹 · Francesco Grippa🇮🇹 · Gaetano Lambiase🇮🇹 · Luca Visinelli🇮🇹

    We investigate axion-like particles coupled to gravity through a parity-violating Chern-Simons (CS) interaction. In this framework, axion dark matter (DM) can decay into pairs of circularly polarized gravitons, producing a persistent, nearly monochromatic GW signal. We compute the expected signal at Earth assuming a Navarro-Frenk-White Galactic halo model with the corresponding velocity distribution, and compare it with the narrowband sensitivities of the LIGO O4 run and the projected reach of the Einstein Telescope. The resulting bounds on the axion-graviton coupling $\alpha$ improve upon the cosmological stability requirement for axion masses $m_{\varphi }\lesssim 10^{-11}$ eV, excluding values up to four orders of magnitude below the stability limit. This constitutes a robust direct terrestrial constraint on the axion-gravity CS coupling. We also discuss distinctive observational signatures, such as circular polarization asymmetries, annual modulation, and potential enhancements from DM substructures, which could serve as smoking-gun evidence for parity-violating gravitational interactions.

    ↳ astro-ph.COhep-phhep-thPRD(2026)·6 citations
39. 39*

    Method of regions for dual conformal integrals

    Leonid V. Bork🇷🇺 · Roman N. Lee🇷🇺 · Andrei I. Onishchenko🇷🇺

    We apply the method of regions to the evaluation of dual conformal integrals with small off-shellness. In contrast to conventional approach, where the separation of regions is performed via dimensional regularization breaking the dual conformal invariance (DCI), we use a sufficiently generic combination of dimensional and analytic regularizations which preserves the DCI. Within this regularization (dubbed as DCI regularization), the contribution of each region becomes DCI. We show that our method dramatically simplifies the calculations. As a demonstration, we calculate the slightly off-shell DCI pentabox integral up to power corrections. The contributions of all 32 regions appear to be expressible in terms of products/ratios of $\Gamma$-functions multiplied by some powers of DCI cross-ratios. Therefore, after removing the regularization, we obtain the final expression in terms of cross-ratios logarithms only. We have checked that our result for pentabox integral numerically agrees with the result of the recent Belitsky\&Smirnov paper [arXiv:2508.14298] which has essentially more complicated form.

    ↳ hep-thhep-phJHEP(2025)·8 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.