Tue·Apr 8, 2025Tuesday·April 8, 2025

1. 01*

   Fragmentation functions for axial-vector heavy tetraquarks: A TQ4Q1.1 update

   Francesco Giovanni Celiberto🇪🇸

   We present and discuss the release of novel sets of collinear, variable-flavor-number-scheme fragmentation functions for axial-vector, fully heavy $T_{4c}(1^{+-})$ and $T_{4b}(1^{+-})$ tetraquarks. Working within the single-parton approximation at leading power and employing nonrelativistic QCD factorization adapted for tetraquark Fock states, we model the initial-scale fragmentation input using a recent calculation for the constituent heavy-quark channel. Standard DGLAP evolution is then applied, ensuring consistent implementation of evolution thresholds. To support phenomenology, we investigate NLL/NLO${}^{+}$ rates for tetraquark-jet systems at the HL-LHC and FCC from (sym)JETHAD. This study further integrates exotic matter explorations with precision QCD calculations.

   hep-phhep-exnucl-exnucl-thPRD(2025)·18 citations
2. 02*

   Probing triple Higgs production via $4\tau 2b$ decay channel at a 100 TeV hadron collider

   Zhenyu Dong🇨🇳 · Xiaohu Sun🇨🇳 · Botao Guo🇨🇳 · Licheng Zhang🇨🇳 · Zhiyuan Li🇨🇳 · Jin Wang🇨🇳 · Zhe Li🇨🇳 · Yong Ban🇨🇳 · Yajun Mao🇨🇳

   A comprehensive study of triple Higgs boson production in the $4\tau 2b$ decay final state is performed for the first time at a future 100 TeV hadron collider. The analysis incorporates modified Higgs self-couplings via trilinear Higgs self-coupling $c_3$ and quartic Higgs self-coupling $d_4$, enabling for a model-independent investigation of potential new physics effects. Higgs bosons are reconstructed using both resolved and boosted techniques. To optimize sensitivity across different kinematic regions, we introduce a novel event categorization strategy based on the triple Higgs invariant mass spectrum and the multiplicity of boosted Higgs bosons. In addition to a traditional cut-based analysis, a Boosted Decision Tree (BDT) approach is employed to exploit multivariate correlations among kinematic observables, leading to a significant improvement in sensitivity. Our result demonstrates that the $4\tau 2b$ channel provides a viable pathway for probing the Higgs quartic coupling, complementing the existing multi-Higgs production studies, and could reach 5 $\sigma$ in significance for $c_3\lesssim -1$ and $d_4\gtrsim 10$ in the scanned range.

   hep-phJHEP(2025)·8 citations
3. 03*

   Signals of critical end point from jet quenching and quark energy loss in holographic QCD

   Zhibin Li🇨🇳 · Danning Li🇨🇳 · Mei Huang🇨🇳

   The jet quenching parameter and energy loss of light and heavy quarks have been investigated in the framework of holographic QCD models with a critical end point (CEP) at finite baryon chemical potential in $N_f=2,2+1,2+1+1$ systems. The properties of the jet quenching parameter and energy loss around CEP have been carefully studied, and some evident signatures for CEP are subtracted. It is found that the dimensionless jet quenching parameter and the energy loss of light and heavy quarks exhibit evident features around CEP. Specifically, all these quantities increase rapidly near the CEP phase transition temperature $T_{CEP}$ with fixed ${\mu }_{CEP}$. Moreover, the velocity dependent behavior of heavy quark energy loss at CEP differs significantly from charged particle energy loss in QED matter. For electromagnetic interaction, the energy loss of charged particle can be described by the Bethe-Bloch formula and the Lindhand-Scharff-Schiott theory at low and high velocities, respectively. However, the heavy quark energy loss at CEP is approximately proportional to velocity at low velocities and aligns with Bjorken's results at high velocities, which indicates that the heavy quark energy loss is predominantly collisional at low velocities and gluon radiation dominant at high velocities. For light quark energy loss, the behavior of the energy loss per unit length and the total energy loss differs significantly. However, the total energy loss and stopping distance exhibit similar behavior. This implies that the stopping distance predominantly determines the total energy loss. Thus, even with increased energy loss per unit length at higher temperatures or chemical potentials, the total energy loss decreases due to the reduced stopping distance.

   hep-phhep-thPRD(2025)·15 citations
4. 04*

   Axion Superradiance in Dipole Magnetic Fields of Pulsars

   Topi Sirkiä🇫🇮 · Matti Heikinheimo🇫🇮 · Kimmo Tuominen🇫🇮

   We consider constraints on the axion-photon coupling by superradiance due to a plasma instability in the magnetospheres of millisecond pulsars. We compute the growth rate of a superradiant axion cloud in a dipole magnetic field, and give a semi-analytical formula for the superradiance rate for the lowest state. By requiring the associated instability time to be longer than the characteristic age of the supermassive black-widow millisecond pulsar PSR J0952-0607, we examine the pulsar-timing array constraints on axions of mass $\sim 10^{-12}\text{ eV}$. We find that competitive axion bounds from plasma instabilities are unlikely unless a new high spin pulsar is discovered.

   hep-phastro-ph.HEPRD(2025)·2 citations
5. 05*

   Higgs Decay Signal Strengths in an Extended 2HDM

   Hrishabh Bharadwaj🇮🇳 · Mamta Dahiya🇮🇳 · Sukanta Dutta🇮🇳 · Ashok Goyal🇮🇳

   The combined CMS and ATLAS analysis of \(h \to Z\gamma\) reveals a \(2\sigma\) excess over the Standard Model (SM) prediction, hinting at potential new physics. In contrast, the observed agreement of \(\mu_{\gamma\gamma}\) with the SM imposes stringent constraints on such extension. In this context, we investigate a Two Higgs Doublet Model (2HDM) extended by a complex scalar singlet and a vector-like lepton (VLL). This framework successfully accommodates the Higgs decay signal strengths \(\mu_{{}_{W \,W^\star}}\), \( \mu_{Z\gamma}\,\), and \(\, \mu_{\gamma\gamma}\) while also satisfying precision electroweak constraints, the observed experimental value of muon \(g-2\), and bounds from LEP II data. We identify a viable region of parameter space that is consistent with all low energy data and current experimental limits on the Higgs decay signal strengths.

   hep-phhep-th0 citations
6. 06*

   Physics with high-luminosity proton-nucleus collisions at the LHC

   D. d'Enterria🇨🇭 · C. A. Flett🇫🇷 · I. Grabowska-Bold🇵🇱 · C. Hadjidakis🇫🇷 · P. Kotko🇵🇱 · A. Kusina🇵🇱 · J.P. Lansberg🇫🇷 · R. McNulty🇮🇪 · M. Rinaldi🇮🇹 · L. Bonechi🇮🇹 · R. Bruce🇨🇭 · C. Da Silva🇺🇸 and 20 other authors

   The physics case for the operation of high-luminosity proton-nucleus ($pA$) collisions during Run 3 and 4 at the LHC is reviewed. The collection of $\mathcal{O}$(1-10 pb${}^{-1}$) of proton-lead ($p$Pb) collisions at the LHC will provide unique physics opportunities in a broad range of topics including proton and nuclear parton distribution functions (PDFs and nPDFs), generalised parton distributions (GPDs), transverse momentum dependent PDFs (TMDs), low-$x$ QCD and parton saturation, hadron spectroscopy, baseline studies for quark-gluon plasma and parton collectivity, double and triple parton scatterings (DPS/TPS), photon-photon collisions, and physics beyond the Standard Model (BSM); which are not otherwise as clearly accessible by exploiting data from any other colliding system at the LHC. This report summarises the accelerator aspects of high-luminosity $pA$ operation at the LHC, as well as each of the physics topics outlined above, including the relevant experimental measurements that motivate -- much -- larger $pA$ datasets.

   hep-phhep-exnucl-exnucl-thJ.Phys.G(2025)·6 citations
7. 07*

   Study of nucleon and $\Delta$ resonances from a systematic analysis of $K^{\ast }\Sigma$ photoproduction

   Jun Shi🇨🇳 · Bing-Song Zou🇨🇳

   A systematic analysis of the $K^{\ast }\Sigma$ photoproduction off proton is performed with all the available differential cross section data. We carry out a strategy different from the previous studies of these reactions, where, instead of fixing the parameters of the added resonances from PDG or pentaquark models, we add the resonance with a specific $J^P$ and leave its parameters to be determined from the experimental data. When adding only one resonance, the best result is to add one $N(3/2^{-})$ resonance around $2097$ MeV, which substantially reduces the ${\chi }^2$ per degree of freedom to $1.35$. There are two best solutions when adding two resonances, one is to add one $N^{\ast }(3/2^{-})$ and one $N^{\ast }(7/2^{-})$, the other is to add one $N^{\ast }(3/2^{-})$ and one ${\Delta }^{\ast }(7/2^{-})$, leading the ${\chi }^2$ per degree of freedom to be $1.10$ and $1.09$, respectively. The mass values of the $N^{\ast }(3/2^{-})$ in the two resonance solutions are both near $2070$ MeV. Our solutions indicate that the $N(3/2^{-})$ resonance around $2080$ MeV is strongly coupled with the $K^{\ast }\Sigma$ final state and support the molecular picture of $N(2080,3/2^{-})$.

   hep-phnucl-thPRD(2025)·2 citations
8. 08*

   Asymmetric Dark Matter in the Sun: A Multicomponent Perspective

   Amit Dutta Banik🇮🇳

   We present a novel concept of enhanced asymmetric dark matter annihilation in astrophysical bodies like the Sun in the presence of multiple dark matter candidates based on hidden annihilation mechanisms. We consider hidden sector annihilation of a heavy dark matter into an asymmetric dark matter, resulting in a significant change in the dark matter annihilation flux and the muon flux at neutrino detectors. We quantify expected changes in the muon flux with scaling parameters for the symmetric or asymmetric nature of the heavier dark matter candidate.

   hep-phastro-ph.SREur.Phys.J.Plus(2025)·0 citations
9. 09*

   Low scale leptogenesis and $T{M}_1$ mixing in neutrinophillic two Higgs doublet model($\nu$2HDM) with S4 flavor symmetry

   Abhishek🇮🇳 · V. Suryanarayana Mummidi

   We study a modified version of the Standard Model that includes a scalar doublet and two right-handed neutrinos, forming the neutrinophillic two higgs doublet ($\nu \text{2HDM}$) framework. For the two Higgs-doublet vacuum expectation values satisfying ${\text{v}}_2<<{\text{v}}_1$, this model operates at a TeV scale, bringing the RHNs within experimental reach. To further enhance its predictive power, we introduce an $S_4\times Z_4$ flavor symmetry with five flavons, resulting in mass matrices that realize the so-called Trimaximal ${\text{TM}}_1$ mixing scheme. The model effectively explains lepton masses and flavor mixing under the normal ordering of neutrino masses, predicting that the effective neutrino mass in 0$\nu \beta \beta$ decay lies between [4 - 5] meV, significantly lower than the sensitivity limits of current experiments. We also investigate how this framework could support low-scale leptogenesis as a natural way to explain the observed imbalance between matter and antimatter in the Universe. This work explores how neutrino physics, flavor symmetry and baryon asymmetry are connected, providing a clear framework that links theoretical predictions with experimental possibilities.

   hep-phPLB(2025)·2 citations
10. 10*

    All-vortex nonlinear Compton scattering in a polarized laser field

    Yi Liao (Nankai U. and South China Normal U.)🇨🇳 · Quan-Yu Wang (Nankai U.)🇨🇳 · Yuanbin Wu (Nankai U.)🇨🇳

    The process of all-vortex nonlinear Compton scattering in an intense and polarized laser field, in which the initial and final electrons and the emitted $\gamma$ photon are all in vortex states, is studied theoretically. We develop a formalism for the process, which allows us to study the exchanges of the orbital angular momentum (OAM) and spin angular momentum among the electron, $\gamma$ photon, and laser. A wave packet of the Bessel-Gaussian type is adopted to describe the initial vortex electron for the purpose of normalization. Both circularly and linearly polarized lasers are examined. Substantial numerical calculations are performed to reveal the physics of the exchanges of the OAM and spin angular momentum. The strong impact of the laser intensity and the opening angle of the initial vortex electron is demonstrated. Our results also suggest possible scenarios for the separation of the emitted $\gamma$ photons with different OAMs, as well as a possible way which could help to distinguish the OAM and spin of the vortex particle by the multi-peak structure in the spectrum of the emitted photon.

    hep-phquant-phPRD(2025)·3 citations
11. 11*

    Challenges in locating the QCD critical point via constant entropy density contours

    Michał Marczenko🇵🇱 · Michał Szymański🇵🇱 · Győző Kovács🇵🇱

    A new method was proposed recently to investigate the location of the putative critical point of strongly interacting matter, governed by quantum chromodynamics. By approximating contours of constant entropy density at finite baryon chemical potential, the conditions for the existence of a critical point are solved. In this work, we analyze this method in the hadron resonance gas and Nambu--Jona-Lasinio models. We demonstrate that the prediction of the critical point in the HRG model is solely due to mesonic and baryonic degrees of freedom, and thus is not necessarily a signal of a critical point. We argue that such an expansion leads to a physically meaningful prediction only when applied near the critical point.

    hep-phPRD(2025)·3 citations
12. 12*

    Study of Fully heavy Pentaquarks using extended Gursey-Radicati formalism

    Ankush Sharma🇮🇳 · Alka Upadhyay🇮🇳

    The study of exotic multi-quark states has garnered significant attention recently, particularly in heavy-quark dynamics within quantum chromodynamics (QCD). We perform a comprehensive spectroscopic analysis of fully heavy pentaquark states with quark configurations $cccc\bar{c}$ and $bbbb\bar{b}$, considering spin-parity quantum numbers $J^P=1/2^{-}$, $3/2^{-}$, and $5/2^{-}$. We construct the color-spin wavefunctions to explore the internal structure and mixing effects in these exotic states. Using an extended form of the Gursey-Radicati mass formula by incorporating spin-dependent interactions, we calculated their mass spectra. The modification incorporates effective mass contributions and hyperfine interactions to improve the predictive power for these hadronic states. We systematically analyze their quantum numbers, including spin parity, isospin, and the eigenvalues of the quadratic Casimir operator, which characterize their symmetry properties. The calculated mass spectra are compared with existing theoretical predictions to assess the stability and possible decay channels of these states. The calculated mass spectra exhibit a strong dependence on the interplay between spin interactions and color configurations, shedding light on the binding mechanism within these fully heavy multiquark systems. To gain further insights into their stability and decay properties, we investigated their potential production modes from $b$-hadron decays. Our analysis identifies dominant strong decay channels, providing critical theoretical benchmarks for distinguishing these states in future LHCb or EIC experiments. This study offers new insights into the role of heavy-quark dynamics in exotic hadron spectroscopy, serving as a stringent test for effective QCD-based models and lattice QCD predictions.

    hep-phFew Body Syst.(2025)·6 citations
13. 13*

    ChPT and lattice QCD studies of doubly charmed baryons

    Ze-Rui Liang🇨🇳 · Jing-Yu Yi🇨🇳 · Liuming Liu🇨🇳 · De-Liang Yao🇨🇳

    The scattering lengths on the interactions between the spin-$1/2$ doubly charmed baryons and Nambu-Goldstone bosons are of great importance for the investigation of the spectroscopy of heavy flavored baryons. To that end, we have conducted a systematic analysis of the low-energy dynamics of doubly charmed baryons within the frameworks of chiral perturbation theory (ChPT) and lattice quantum chromodynamics (QCD). On the one hand, the S- and P-wave scattering lengths are predicted in a manifestly relativistic baryon ChPT at leading one-loop order. On the other hand, results of the S-wave scattering lengths for four elastic scattering single channels are obtained in lattice QCD for the first time.

    hep-phhep-exhep-latPoS(2026)·2 citations
14. 14*

    Dark energy under a gauge symmetry: A review of gauged quintessence and its implications

    Kunio Kaneta🇯🇵 · Hye-Sung Lee🇰🇷 · Jiheon Lee🇰🇷 · Jaeok Yi🇰🇷

    We review the gauged quintessence scenario, wherein the quintessence scalar field responsible for dark energy is promoted to a complex field charged under a dark $U(1)$ gauge symmetry. This construction leads to new and potentially rich cosmological phenomenology. After a concise recap of the standard quintessence scenario, we highlight how a $U(1)$ gauge invariance alters the dynamics of the scalar and the associated dark gauge boson. We survey the evolution of both fields across cosmic history, discuss their possible production via a misalignment mechanism, and examine implications for the Hubble tension. We also comment on potential non-gravitational signals of gauged quintessence through kinetic mixing (the dark photon vector portal).

    hep-phastro-ph.COInt.J.Mod.Phys.A(2025)·4 citations
15. 15*

    Charmonium-nucleon femtoscopic correlation function

    Zhi-Wei Liu🇨🇳 · Duo-Lun Ge🇨🇳 · Jun-Xu Lu🇨🇳 · Ming-Zhu Liu🇨🇳 · Li-Sheng Geng🇨🇳

    This study investigates the femtoscopic correlation functions of charmonium-nucleon pairs, utilizing the lattice QCD phase shifts provided by the HAL QCD Collaboration. A ``model-independent'' formalism is employed to transform scattering phase shifts directly into momentum correlation functions, thereby circumventing the approximations inherent in traditional methods, such as the Lednický-Lyuboshits model. The $J/\psi$-$p$ correlation functions, including spin-averaged and partial-wave results, are predicted using near-physical pion mass lattice results. The ${\eta }_c$-$p$ correlation function is calculated for the first time. The derived correlation functions provide critical references for future experiments, such as those at the LHC, where high-precision measurements of charmonium-nucleon correlations could unveil valuable insights into non-perturbative QCD dynamics.

    hep-phnucl-thPRD(2025)·16 citations
16. 16*

    Investigation of the baryon time-like electromagnetic form factors in the electron-positron annihilation reactions

    Ju-Jun Xie🇨🇳 · Cheng Chen🇨🇳

    Based on the experimental measurements of the electron-positron annihilation reactions into a baryon ($B$) and anti-baryon ($\bar{B}$) pair, the electromagnetic form factors of hyperons in the time-like region can be investigated within the vector meson dominance model. The theoretical model parameters are determined by fitting them to the total cross sections of the process $e^{+}{e}^{-}\to B\bar{B}$, and it is found that the current experimental data on the baryon electromagnetic form factors in the time-like region can be well reproduced. In addition to the total cross sections, the electromagnetic form factors $G_E$ and $G_M$, and the charge radii of those baryons are also estimated, which are in agreement with the experimental data. On the other hand, we have also investigated the nonmonotonic behavior of the time-like baryon electromagnetic form factors, and it is found that the previously proposed periodic behaviour of the nucleon time-like electromagnetic form factor is not confirmed. However, we do observe the nonmonotonic structures in the line shape of the baryon effective form factors or the ratio $|G_E/G_M|$ for the charmed baryon ${\Lambda }_c^{+}$. These features can be naturally explained by incorporating contributions from excited vector states. More precise measurements of the $e^{+}{e}^{-}\to B\bar{B}$ reaction offer a valuable opportunity to probe the properties of excited vector states, which are at present poorly known. Additionally, comprehensive theoretical and experimental studies of baryon timelike electromagnetic form factors can provide critical insights into the underlying mechanisms of electron-positron annihilation processes.

    hep-phhep-exnucl-exnucl-thPoS(2025)·0 citations
17. 17*

    Light quark energy loss in the flavor-dependent systems from holography

    Le Zhang🇨🇳 · Lu Yin🇨🇳 · Guo-Dong Zhou🇨🇳 · Chao-Jie Fan🇨🇳 · Xun Chen🇨🇳

    Using the holographic model of finite-endpoint-momentum shooting string approach, we study the instantaneous energy loss of light quarks for the flavor-dependent systems with $N_f=0$, $N_f=2$, and $N_f=2+1$ in the Einstein-Maxwell-dilaton (EMD) framework. In particular, we investigate for the first time the impact of the flavor content of the strongly coupled QGP medium on the instantaneous energy loss of light quarks. It turns out that the instantaneous energy loss of light quarks is smallest for $N_f=0$, and adding $u(d)$ quarks and $s$ quark in the system increases this energy loss. In addition, we found that the instantaneous energy loss in the strongly coupled plasma is minimal near the critical temperature, but it increases as the system moves away from the critical endpoint due to rising temperature or chemical potential.

    hep-phPRD(2025)·5 citations
18. 18*

    Experimental Constraints on Seesaw Parameters in the Wigner-like Parametrization

    Jihong Huang🇨🇳

    By introducing three right-handed neutrino singlets, the popular canonical seesaw mechanism is able to simultaneously explain the tiny masses of Majorana neutrinos and the baryon asymmetry of the Universe. In this paper, we provide an explicit calculation in this model with the help of the Wigner-like parametrization. We work in a special ansatz where both ${\mathbf{m}}_{\mathrm{D}}^{†}{\mathbf{m}}_{\mathrm{D}}^{}$ and ${\mathbf{m}}_{\mathrm{R}}^{†}{\mathbf{m}}_{\mathrm{R}}^{}$ are diagonal, with ${\mathbf{m}}_{\mathrm{D}}^{}$ and ${\mathbf{m}}_{\mathrm{R}}^{}$ being accordingly the Dirac and Majorana neutrino mass matrices, and $[{\mathbf{m}}_{\mathrm{D}}^{†}{\mathbf{m}}_{\mathrm{D}}^{},{\mathbf{m}}_{\mathrm{R}}^{†}{\mathbf{m}}_{\mathrm{R}}^{}]=0$ holds. Physical observables can be exactly calculated without any approximation, where three light Majorana neutrino masses $m_i^{}$, leptonic mixing angles ${\theta }_{ij}^{}$, CP-violating phases $\{\delta ,\rho ,\sigma \}$, and three rotation angles ${\vartheta }_i^{}$ describing the hierarchy between electroweak and seesaw scales are chosen as input parameters. For demonstration, we evaluate the branching fractions of the lepton-flavor-violating decays of charged leptons and the CP-violating asymmetries in the resonant thermal leptogenesis. The model parameters are constrained by the latest experimental limits.

    hep-phhep-exPLB(2025)·0 citations
19. 19*

    Finite density signatures of confining and chiral dynamics in QCD thermodynamics and fluctuations of conserved charges

    Yi Lu🇨🇳 · Fei Gao🇨🇳 · Yu-xin Liu🇨🇳 · Jan M. Pawlowski🇩🇪

    We evaluate thermodynamic observables such as pressure, baryon number, entropy and energy density, as well as the second and fourth order baryon number cumulants in the phase structure of QCD. The intertwined confinement and chiral dynamics is resolved within functional QCD, aiming for quantitative accuracy at larger densities. Specifically it is shown that the self-consistent resolution of the confining gluonic background is crucial in particular for even the qualitative properties of the cumulants. Our results are in quantitative agreement with lattice and functional QCD benchmarks at vanishing and small chemical potentials. Moreover, they offer novel insights in the dynamics at larger chemical potentials including the regime of the critical end point. A welcome by-product of this analysis is the computation of the Polyakov loop potential in finite density QCD, which, alongside the aforementioned observables, can be used as input and benchmark for effective theory computations at finite density.

    hep-phhep-thnucl-exnucl-thPRD(2026)·31 citations
20. 20*

    One-loop transverse-momentum-dependent soft function at higher orders in the dimensional regulator

    Hua-Sheng Shao🇫🇷 · Guoxing Wang🇫🇷

    The transverse-momentum-dependent (TMD) soft function for a generic hadroproduction process involving massive colored particles is analytically calculated at the one-loop level, extended to higher orders in the dimensional regulator $ϵ$. We present both the azimuthal-angle-averaged and azimuthal-angle-dependent soft functions in impact-parameter space, making them suitable for small $q_T$ resummation calculations. Their analytic expressions are provided in terms of multiple polylogarithms. Our results offer essential ingredients for a complete higher-order perturbative calculation of the TMD soft function.

    hep-phnucl-thJHEP(2025)·6 citations
21. 21*

    Detailed $SU(3)$ Flavour Symmetry Analysis of Charmless Two-Body $B$-Meson Decays Including Factorizable Corrections

    M. Burgos Marcos🇳🇱 · M. Reboud🇫🇷 · K. K. Vos🇳🇱

    We study the decays of $B_{(s)}$ mesons into light pseudoscalar mesons under the $SU(3)$ flavour symmetry. Assuming exact $SU(3)$ symmetry at the level of the amplitudes leads to a simple parameterization. Using the available experimental data and, for the first time, mixing effects in the $B_s^0$ decays, we find that the data cannot be described with this assumption. We improve this parametrization by including {\it factorizable} $SU(3{)}_{\mathrm{F}}$-breaking effects. This new approach allows for an excellent description of the data, with a fit $p$ value of $32.3\%$. We provide posterior predictions for all observables and identify several decay channels that would significantly impact our analysis. Finally, we briefly compare our results with the predictions of QCD factorization, paving the way to a more detailed analysis which could provide insights into QCD effects at low energy scales.

    hep-phJHEP(2026)·15 citations
22. 22*

    Precision DIS thrust predictions for HERA and EIC

    June-Haak Ee🇺🇸 · Daekyoung Kang🇨🇳 · Christopher Lee🇺🇸 · Iain W. Stewart🇺🇸

    We present predictions for the DIS 1-jettiness event shape ${\tau }_1^b$, or DIS thrust, using the framework of Soft Collinear Effective Theory (SCET) for factorization, resummation of large logarithms, and rigorous treatment of nonperturbative power corrections, matched to fixed-order QCD away from the resummation region. Our predictions reach next-to-next-to-next-to-leading-logarithmic (N${}^3$LL) accuracy in resummed perturbation theory, matched to $O({\alpha }_s^2)$ fixed-order QCD calculations obtained using the program NLOJet++. We include a rigorous treatment of hadronization corrections, which are universal across different event shapes and kinematic variables $x$ and $Q$ at leading power, and supplement them with a systematic scheme to remove $O({\Lambda }_{\text{QCD}})$ renormalon ambiguities in their definition. The framework of SCET allows us to connect smoothly the nonperturbative, resummation, and fixed-order regions, whose relative importance varies with $x$ and $Q$, and to rigorously estimate theoretical uncertainties, across a broad range of $x$ and $Q$ covering existing experimental results from HERA as well as expected new measurements from the upcoming Electron-Ion-Collider (EIC). Our predictions will serve as an important benchmark for the EIC program, enabling the precise determination of the QCD strong coupling ${\alpha }_s$ and the universal nonperturbative first moment parameter ${\Omega }_1$.

    hep-phnucl-thJHEP(2025)·10 citations
23. 23*

    Standard Model Tested with Neutrinos

    Mattia Atzori Corona🇮🇹 · Matteo Cadeddu🇮🇹 · Nicola Cargioli🇮🇹 · Francesca Dordei🇮🇹 · Carlo Giunti🇮🇹 · Christoph A. Ternes🇮🇹

    The Standard Model (SM) of particle physics effectively explains most observed phenomena, though some anomalies, especially in the neutrino sector, suggest the need for extensions. In this Letter, we perform the first global fit of elastic neutrino-nucleus and neutrino-electron scattering data to further test the SM within a consistent framework. Our results on the neutrino charge radius, the only nonzero electromagnetic property of neutrinos in the SM, show no significant deviation, indicating no large beyond the SM flavor-dependent effects for electron and muon neutrinos. By incorporating solar neutrino data from dark matter direct detection experiments, we also place the most stringent constraints on the tau neutrino charge radius obtained from neutrino scattering experiments. Additionally, we determine updated constraints on the vector and axial-vector neutrino-electron neutral current couplings, adjusting for flavor-dependent effects and for the different experimental momentum transfers. The global analysis reveals two allowed solutions: one close to the SM prediction, and a degenerate solution that is favored. We show that future dark matter detectors could achieve sufficient precision to resolve the degeneracy. As we move toward the precision era, this Letter demonstrates the crucial need to properly account for flavor- and momentum-dependent effects to avoid misinterpretations of the data.

    hep-phhep-exPRL(2025)·15 citations
24. 24*

    Neutrino Oscillations as a Probe of Macrorealism

    Kathrine Mørch Groth🇩🇰 · Johann Ioannou-Nikolaides🇩🇰 · D. Jason Koskinen🇩🇰 · Markus Ahlers🇩🇰

    The correlations between successive measurements of a quantum system can violate a family of Leggett-Garg Inequalities (LGIs) that are analogous to the violation of Bell's inequalities of measurements performed on spatially separated quantum systems. These LGIs follow from a macrorealistic point of view, imposing that a classical system is at all times in a definite state and that a measurement can, at least in principle, leave this state undisturbed. Violations of LGIs can be probed by neutrino flavour oscillations if the correlators of consecutive flavour measurements are approximately stationary. We discuss here several improvements of the methodology used in previous analyses based on accelerator and reactor neutrino data. We argue that the strong claims of LGI violations made in previous studies are based on an unsuitable modelling of macrorealistic systems in statistical hypothesis tests. We illustrate our improved methodology via the example of the MINOS muon-neutrino survival data, where we find revised statistical evidence for violations of LGIs at the $(2-3)\sigma$ level, depending on macrorealistic background models.

    hep-phastro-ph.HEquant-phPRD(2025)·3 citations
25. 25*

    Identified Hadron Production in Deeply Inelastic Neutrino-Nucleon Scattering

    Leonardo Bonino🇨🇭 · Thomas Gehrmann🇨🇭 · Markus Löchner🇨🇭 · Kay Schönwald🇨🇭 · Giovanni Stagnitto🇮🇹

    The production of identified hadrons in semi-inclusive deep-inelastic scattering (SIDIS) is sensitive to parton distribution functions and hadron fragmentation functions. Neutrino-induced SIDIS processes probe combinations of these functions different from their charged-lepton-induced counterparts. We compute charged pion production in (anti-)neutrino induced SIDIS up to second order in perturbative QCD and compare our predictions to precise legacy fixed-target data. We demonstrate the high sensitivity of these data on the parametrization of the fragmentation functions and discuss future SIDIS probes at the LHC Forward Physics Facility.

    hep-phhep-exPRL(2025)·13 citations
26. 26*

    Logarithmically-accurate and positive-definite NLO shower matching

    Melissa van Beekveld🇳🇱 · Silvia Ferrario Ravasio🇨🇭 · Jack Helliwell🇦🇺 · Alexander Karlberg🇨🇭 · Gavin P. Salam🇬🇧 · Ludovic Scyboz🇦🇺 · Alba Soto-Ontoso🇪🇸 · Gregory Soyez🇫🇷 · Silvia Zanoli🇬🇧

    We present methods to achieve NLL+NLO accurate parton showering for processes with two coloured legs: neutral- and charged-current Drell-Yan, and Higgs production in $pp$ collisions, as well as DIS and $e^{+}{e}^{-}$ to jets. The methods include adaptations of existing approaches, as well as a new NLO matching scheme, ESME, that is positive-definite by construction. Our implementations of the methods within the PanScales framework yield highly competitive NLO event generation speeds. We validate the fixed-order and combined resummation accuracy with tests in the limit of small QCD coupling and briefly touch on phenomenological comparisons to standard NLO results and to Drell-Yan data. The progress reported here is an essential step towards showers with logarithmic accuracy beyond NLL for processes with incoming hadrons.

    hep-phJHEP(2025)·24 citations
27. 27*

    Neutrino properties from muonium-antimuonium mixing

    Mitrajyoti Ghosh🇺🇸 · Kevin Liguori🇺🇸 · Takemichi Okui🇺🇸 · Kohsaku Tobioka🇺🇸

    The nature of neutrino mass -- whether neutrinos are Dirac or Majorana particles -- remains one of the central open questions in particle physics. While observation of neutrinoless double beta decay would confirm the Majorana case, the absence of a signal offers no definitive insight. In light of this, we investigate muonium-antimuonium mixing -- proposed for further study at the MACE experiment -- as an alternative probe of neutrino properties. We compute the mixing amplitude in the Standard Model minimally extended to include massive Dirac or Majorana neutrinos, and correct previous calculations by properly treating the relevant infrared scales. As the GIM mechanism strongly suppresses the Dirac contribution, we explore whether relaxing unitarity of the PMNS matrix can enhance the mixing without obscuring neutrino properties. Surprisingly, the answer to this question is negative. We also examine the pseudo-Dirac case -- predominantly Dirac neutrinos with small Majorana masses -- and find that this scenario can significantly enhance the mixing compared to the pure Dirac case, especially for normal mass ordering.

    hep-phJHEP(2025)·2 citations
28. 28*

    Supercooled Audible Axions

    Christopher Gerlach🇩🇪 · Daniel Schmitt🇩🇪 · Pedro Schwaller🇩🇪

    In the audible axion mechanism, axion-like particles source primordial gravitational waves via their coupling to a dark Abelian gauge field. The original setup, however, relies on a large axion decay constant and coupling to produce sizable signals. In this article, we show that delaying the onset of axion oscillations opens up the testable parameter space and reduces the required coupling to $\alpha \gtrsim 1$. Furthermore, we investigate the emission of gravitational waves via the axion coupling to the Standard Model photon in the presence of Schwinger pair production, generating a strong signal in the $\mu$Hz or ultra-high frequency range. Cosmological constraints and gravitational wave projections are provided for both scenarios.

    hep-phastro-ph.COJHEP(2025)·6 citations
29. 29*

    Primordial Stochastic Gravitational Waves from Massive Higher-Spin Bosons

    Haipeng An🇨🇳 · Zhehan Qin🇨🇳 · Zhong-Zhi Xianyu🇨🇳 · Borui Zhang🇨🇳

    Can a stationary stone radiate gravitational waves (GWs)? While the answer is typically "no" in flat spacetime, we get a "yes" in inflationary spacetime. In this work, we study the stationary-stone-produced GWs in inflation with a concrete model, where the role of stones is played by massive higher-spin particles. We study particles of spin-2 and higher produced by helical chemical potentials, and show that the induced GWs feature a scale-invariant and helicity-biased power spectrum in the slow-roll limit. Including slow-roll corrections leads to interesting backreactions from the higher-spin boson production, resulting in an intriguing scale-dependence of GWs at small scales. Given the existing observational and theoretical constraints, we identify viable parameter regions capable of generating visibly large GWs for future observations.

    hep-phastro-ph.COhep-thJHEP(2025)·4 citations
30. 30*

    SageNet: Fast Neural Network Emulation of the Stiff-amplified Gravitational Waves from Inflation

    Fan Zhang🇨🇳 · Yifang Luo🇨🇳 · Bohua Li🇨🇳 · Ruihan Cao🇺🇸 · Wenjin Peng🇨🇳 · Joel Meyers🇺🇸 · Paul R. Shapiro🇺🇸

    Accurate modeling of the inflationary gravitational waves (GWs) requires time-consuming, iterative numerical integrations of differential equations to take into account their backreaction on the expansion history. To improve computational efficiency while preserving accuracy, we present SageNet (Stiff-Amplified Gravitational-wave Emulator Network), a deep learning framework designed to replace conventional numerical solvers. SageNet employs a Long Short-Term Memory architecture to emulate the present-day energy density spectrum of the inflationary GWs with possible stiff amplification, ${\Omega }_{\mathrm{GW}}(f)$. Trained on a data set of 25,689 numerically generated solutions, SageNet allows accurate reconstructions of ${\Omega }_{\mathrm{GW}}(f)$ and generalizes well to a wide range of cosmological parameters; 89.3% of the test emulations with randomly distributed parameters exhibit errors of under 4%. In addition, SageNet demonstrates its ability to learn and reproduce the artificial, adaptive sampling patterns in numerical calculations, which implement denser sampling of frequencies around changes of spectral indices in ${\Omega }_{\mathrm{GW}}(f)$. The dual capability of learning both physical and artificial features of the numerical GW spectra establishes SageNet as a robust alternative to exact numerical methods. Finally, our benchmark tests show that SageNet reduces the computation time from tens of seconds to milliseconds, achieving a speed-up of ~$10^4$ times over standard CPU-based numerical solvers with the potential for further acceleration on GPU hardware. These capabilities make SageNet a powerful tool for accelerating Bayesian inference procedures for extended cosmological models. In a broad sense, the SageNet framework offers a fast, accurate, and generalizable solution to modeling cosmological observables whose theoretical predictions demand costly differential equation solvers.

    ↳ astro-ph.COgr-qchep-phAstrophys.J.Suppl.(2025)·3 citations
31. 31*

    Unveiling the Coma Cluster Structure: From the Core to the Hubble Flow

    David Benisty🇩🇪 · Jenny Wagner🇮🇱 · Sandeep Haridasu🇮🇹 · Paolo Salucci🇮🇹

    The Coma cluster, embedded in a cosmic filament, is a complex and dynamically active structure in the local Universe. Applying a density-based member selection dbscan to data from the Sloan Digital Sky Survey (SDSS), we identify cluster member galaxies from its virialised core out to the zero-velocity boundary in the least model-dependent way. From dbscan, we infer a projected virial radius of $r_{\mathrm{vir}}=\left(1.95\pm 0.12\right)h^{-1}\text{Mpc}$ and projected zero-velocity radius of $r_{\mathrm{ta}}\ge 4.87h^{-1}\text{mbox}Mpc$. Assuming that the barycentre of Coma has zero peculiar velocity, its distance from us is $r_{\mathrm{c}}=(69.959\pm 0.012_{\mathrm{stat}})h^{-1}\text{Mpc}$ determined from the redshifts of 1092 member galaxies. Cross-correlating with the Cosmicflows-4 (CF4) catalogue enables a velocity-distance analysis. This reveals, for the first time, the Hubble flow surrounding Coma, a first step to investigate the entanglement between Coma's dark matter halo and the dark energy driving the expansion of the surroundings. If $v_{\mathrm{c}}$ is moving with the cosmic expansion, the CF4 distances yield a Hubble constant $H_0=(73\pm 1_{\mathrm{stat}}\pm 7_{\mathrm{sys}})\text{mbox}km/\text{mbox}s/\text{mbox}Mpc$ with a dominating systematic error from different calibrations for the distance moduli. Mass estimates via caustics, the virial theorem, and the Hubble-flow method yield $M=[0.77,2.0]\times 10^{15}{h}^{-1}{M}_{\odot }$ consistent with prior mass estimates. Our mass estimates are based on fewer model assumptions in the member selection and require $\sim 20\%$ members to attain the same precision. Our approach maps the structure of Coma into its Hubble flow and shows degeneracies between the Hubble constant, the virial radius, and the total mass only using data and models from the single line-of-sight towards Coma.

    ↳ astro-ph.COastro-ph.GAastro-ph.IMgr-qc+1JCAP(2026)·15 citations
32. 32*

    Gravitational dark matter production from fermionic spectator fields during inflation

    Alessio Belfiglio🇮🇹 · Orlando Luongo🇮🇹

    We investigate the gravitational particle production from vacuum for a minimally coupled fermionic spectator field during a single-field inflationary phase. We observe that metric perturbations arising from the quantum fluctuations of a scalar inflaton field enhance gravitational production, showing that such a perturbative contribution becomes dominant if the field mass is sufficiently smaller than the inflationary Hubble rate. We focus on modes that leave the Hubble horizon during the latest stages of slow-roll and we numerically compute the total number of particles obtained from perturbations, providing a lower bound on the amount of such \enquote{geometric} particles for the case of Starobinsky inflation and a quadratic hilltop scenario. Our outcomes are compatible with the net observational cold dark matter abundance as experimentally measured, whose dark matter candidate exhibits mass in the range $10^5\lesssim m\lesssim 10^7$ GeV, excluded by previous non-perturbative calculations.

    ↳ gr-qcastro-ph.COhep-phhep-thJHEP(2025)·6 citations
33. 33*

    Has DESI detected exponential quintessence?

    Yashar Akrami🇪🇸 · George Alestas🇪🇸 · Savvas Nesseris🇪🇸

    The new Dark Energy Spectroscopic Instrument (DESI) DR2 results have strengthened the possibility that dark energy is dynamical, i.e., it has evolved over the history of the Universe. One simple, but theoretically well motivated and widely studied, physical model of dynamical dark energy is minimally coupled, single-field quintessence $\varphi$ with an exponential potential $V(\varphi )=V_0{e}^{-\lambda \varphi }$. We perform a full Bayesian statistical analysis of the model using the DESI DR2 data, in combination with other cosmological observations, to constrain the model's parameters and to compare its goodness of fit to that of the standard $\Lambda$CDM model. We find that the quintessence model provides a significantly better fit to the data, both when the spatial curvature of the Universe is fixed to zero and when it is allowed to vary. The significance of the preference varies between $\sim 3.3\sigma$ and $\sim 3.8\sigma$, depending on whether the curvature density parameter ${\Omega }_K$ is fixed or varied. We obtain the values $0.698_{-0.202}^{+0.173}$ and $0.722_{-0.208}^{+0.182}$ at the $68.3\%$ (i.e., $1\sigma$) confidence level for the parameter $\lambda$ in the absence and presence of ${\Omega }_K$, respectively, which imply $\sim 3.5\sigma$ preference for a nonzero $\lambda$. We also obtain ${\Omega }_K=0.003\pm 0.001$, which implies $\sim 3\sigma$ preference for a positive ${\Omega }_K$, i.e., a negative curvature. Finally, we discuss the differences between quintessence and phenomenological parametrizations of the dark energy equation-of-state parameter, in particular the Chevallier-Polarski-Linder (CPL) parametrization, as well as a few caveats to our results.

    ↳ astro-ph.COgr-qchep-phhep-th49 citations
34. 34*

    How much has DESI dark energy evolved since DR1?

    Eoin Ó Colgáin🇮🇪 · Saeed Pourojaghi🇮🇷 · M.M. Sheikh-Jabbari🇮🇷 · Lu Yin🇨🇳

    DESI has reported a dynamical dark energy (DE) signal based on the $w_0{w}_a$CDM model that is in conflict with Hubble tension. Recalling that the combination of DESI DR1 BAO and DR1 full-shape (FS) modeling are consistent with $\Lambda$CDM, in this letter we comment on the status of fluctuations in DR1 BAO documented in \cite{DESI:2024mwx, Colgain:2024xqj} in the DR2 update. In particular, we note that neither DR1 BAO nor DR2 BAO nor DR2 BAO+CMB confronted to the $w_0{w}_a$CDM model with relaxed model parameter priors confirm late-time accelerated expansion today. Translating DESI BAO constraints into flat $\Lambda$CDM constraints, we observe that the LRG1 constraint remains the most prominent outlier, a distinction now held jointly with ELG1, LRG2 switches from smaller to larger ${\Omega }_m$ values relative to Planck-$\Lambda$CDM, and ELG data drive the relatively low ${\Omega }_m$ in the full DR2 BAO. We observe that one cannot restore $w_0=-1$ within one $1\sigma$ by removing either LRG1 or ELG1 or LRG2, but LRG2 in DR2, in contrast to LRG1 in DR1, now has the greatest bearing on $w_0>-1$. We conclude that BAO has yet to stabilise, but the general trend is towards greater consistency with DESI DR1 FS modeling results, where there may be no dynamical DE signal in DESI data alone.

    ↳ astro-ph.COhep-phhep-thPhys.Dark Univ.(2026)·78 citations
35. 35*

    Transverse-momentum-dependent pion structures from lattice QCD: Collins-Soper kernel, soft factor, TMDWF, and TMDPDF

    Dennis Bollweg🇺🇸 · Xiang Gao🇺🇸 · Jinchen He🇺🇸 · Swagato Mukherjee🇺🇸 · Yong Zhao🇺🇸

    We present the first lattice quantum chromodynamics (QCD) calculation of the pion valence-quark transverse-momentum-dependent parton distribution function (TMDPDF) within the framework of large-momentum effective theory (LaMET). Using correlators fixed in the Coulomb gauge (CG), we computed the quasi-TMD beam function for a pion with a mass of 300 MeV, a fine lattice spacing of $a=0.06$ fm and multiple large momenta up to 3 GeV. The intrinsic soft functions in the CG approach are extracted from form factors with large momentum transfer, and as a byproduct, we also obtain the corresponding Collins-Soper (CS) kernel. Our determinations of both the soft function and the CS kernel agree with perturbation theory at small transverse separations ($b_{\perp }$) between the quarks. At larger $b_{\perp }$, the CS kernel remains consistent with recent results obtained using both CG and gauge-invariant TMD correlators in the literature. By combining next-to-leading logarithmic (NLL) factorization of the quasi-TMD beam function and the soft function, we obtain $x$-dependent pion valence-quark TMDPDF for transverse separations $b_{\perp }\gtrsim 1$ fm. Interestingly, we find that the $b_{\perp }$ dependence of the phenomenological parameterizations of TMDPDF for moderate values of $x$ are in reasonable agreement with our QCD determinations. In addition, we present results for the transverse-momentum-dependent wave function (TMDWF) for a heavier pion with 670 MeV mass.

    ↳ hep-lathep-exhep-phnucl-ex+1PRD(2025)·33 citations
36. 36*

    Identifying $\alpha$-cluster configurations in ${}^{20}$Ne via ultracentral Ne+Ne Collisions

    Pei Li🇨🇳 · Bo Zhou🇨🇳 · Guo-Liang Ma🇨🇳

    The initial-state geometry in relativistic heavy-ion collisions provides a novel probe to nuclear cluster structure. For ${}^{20}$Ne, a novel approach is proposed to distinguish between the cluster configurations (5$\alpha$ versus $\alpha {+}^{16}$O) in order to gain insight into nuclear structure transitions governed by many-body quantum correlations. Through analytical calculations with the microscopic Brink model and event-by-event simulations using the hydrodynamic framework, we establish the normalized symmetric cumulant NSC (3, 2) and the Pearson coefficient ${\rho }_2(v_2^2,\delta [p_{\mathrm{T}}])$ as quantitative discriminators to reveal enhanced cluster degrees of freedom in the ground state of ${}^{20}$Ne. The ultracentral Ne+Ne collisions at the LHC can experimentally identify these two competing configurations via these flow correlation observables, opening a new paradigm for probing clustering in light nuclei.

    ↳ nucl-thhep-phnucl-exPRL(2026)·15 citations
37. 37*

    Novel Polarimetric Analysis of Near Horizon Flaring Episodes in M87* in Millimeter Wavelength

    Razieh Emami · Matthew Liska · Koushik Chatterjee🇺🇸 · Geoffrey C. Bower · Wystan Benbow🇺🇸 · Douglas Finkbeiner · Maciek Wielgus🇩🇪 · Lars Hernquist🇺🇸 · Randall Smith · Grant Tremblay · Angelo Ricarte · James F. Steiner and 6 other authors

    Recent multi-wavelength observations of M87* \citep{2024A&A...692A.140A} revealed a high-energy $\gamma$-ray flare without a corresponding millimeter counterpart. We present a theoretical polarimetric study to evaluate the presence and nature of a potential millimeter flare in M87*, using a suite of general relativistic magnetohydrodynamical simulations with varying black hole (BH) spins and magnetic field configurations. We find that the emergence of a millimeter flare is strongly influenced by both spin and magnetic structure, with limited sensitivity to the electron distribution (thermal vs. non-thermal). We model the intensity light curve with a damped random walk (DRW) and compare the characteristic timescale ($\tau$) with recent SMA observations, finding that the simulated $\tau$ exceeds observed values by over an order of magnitude. In a flaring case with BH spin a=+0.5, we identify a distinct millimeter flare followed by an order-of-magnitude flux drop. All Stokes parameters show variability near the flare, including a sign reversal in the electric vector position angle. While most ${\beta }_m$ modes remain stable, the $EB$-correlation phase is highly sensitive to both the flare peak and decay. We examine polarimetric signatures in photon sub-rings, focusing on modes ns=0 and ns=1. The ns=0 signal closely matches the full image, while ns=1 reveals distinct behaviors, highlighting the potential of space VLBI to isolate sub-ring features. Finally, we analyze the magnetic and velocity field evolution during the flare, finding that magnetic reconnection weakens during the flux decay, and the clockwise velocity flow transitions into an outflow-dominated regime. These results suggest that transient radio variability near flares encodes key information about black hole spin and magnetic field structure, offering a novel probe into the physics of active galactic nuclei.

    ↳ astro-ph.HEastro-ph.GAhep-phhep-thApJ(2026)·1 citation
38. 38*

    Perturbation theory of rotating scalar fields and vacuum insensitivity to rotation

    Ryo Kuboniwa🇯🇵 · Kazuya Mameda🇯🇵

    We formulate the finite-temperature perturbation theory of interacting scalar fields under external rotation. Because of the translational non-invariance in the radial direction, Green's functions are described using the Fourier-Bessel basis, instead of the conventional Fourier basis. We derive the leading-order correction to the partition function and the one-loop self-energy. The Feynman rules obtained in our perturbation theory shows that due to the finite-size effect required by the causality constraint, the zero-temperature thermodynamics in the perturbation theory is unaffected by rotation, similarly to that in the noninteracting theory.

    ↳ hep-thhep-phnucl-thPLB(2026)·7 citations
39. 39*

    Characterized behaviors of black hole thermodynamics in the supercritical region

    Zi-Qiang Zhao🇺🇸 · Zhang-Yu Nie🇨🇳 · Jing-Fei Zhang🇺🇸 · Xin Zhang🇺🇸

    The comprehension of universal thermodynamic behaviors in the supercritical region is crucial for examining the characteristics of black hole systems under high temperature and pressure. This study is devoted to the analysis of characteristic lines and crossover behaviors within the supercritical region. By making use of the free energy, we introduce three key thermodynamic quantities: scaled variance, skewness, and kurtosis. Our results demonstrate that the Widom line, associated with the maximal scaled variance, can effectively differentiate between small and large black hole-like subphases, each displaying distinct thermodynamic behaviors within the supercritical region. Furthermore, by utilizing quasinormal modes, we identify the Frenkel line, offering a dynamic perspective to distinguish between small and large black hole-like subphases. These contribute to a deeper comprehension of black hole subphases in the supercritical region, thus illuminating new facets of black hole thermodynamics.

    ↳ gr-qcastro-ph.COhep-phhep-thChin.Phys.Lett.(2025)·22 citations
40. 40*

    Learning symmetries in datasets

    Veronica Sanz🇪🇸

    We investigate how symmetries present in datasets affect the structure of the latent space learned by Variational Autoencoders (VAEs). By training VAEs on data originating from simple mechanical systems and particle collisions, we analyze the organization of the latent space through a relevance measure that identifies the most meaningful latent directions. We show that when symmetries or approximate symmetries are present, the VAE self-organizes its latent space, effectively compressing the data along a reduced number of latent variables. This behavior captures the intrinsic dimensionality determined by the symmetry constraints and reveals hidden relations among the features. Furthermore, we provide a theoretical analysis of a simple toy model, demonstrating how, under idealized conditions, the latent space aligns with the symmetry directions of the data manifold. We illustrate these findings with examples ranging from two-dimensional datasets with $O(2)$ symmetry to realistic datasets from electron-positron and proton-proton collisions. Our results highlight the potential of unsupervised generative models to expose underlying structures in data and offer a novel approach to symmetry discovery without explicit supervision.

    ↳ cs.LGhep-phAppl.Sciences(2026)·2 citations
41. 41*

    Equivalence Theorems and Double-Copy Structure in Scattering Amplitudes of Massive Kaluza-Klein States with Matter Interactions

    Kezhu Guo🇺🇸 · Yanfeng Hang🇺🇸

    We investigate the scattering amplitudes of massive Kaluza-Klein (KK) states in compactified five-dimensional warped gauge and gravity theories. Focusing on tree-level $2\to 2$ processes, we analyze the leading-order amplitudes involving bulk KK matter fields and KK gauge/gravitational Goldstone bosons. By imposing the gauge theory equivalence theorem (GAET) and the gravitational equivalence theorem (GRET) within warped KK theories, we systematically reconstruct the leading-order amplitudes for physical KK gauge bosons and gravitons, thereby circumventing the intricate energy cancellations inherent in physical amplitudes. Within this framework, the correspondence between GAET and GRET arises as a direct manifestation of the leading-order double-copy relation in the high-energy expansion. This connection provides a foundation for extending the BCJ double-copy construction to four-point amplitudes involving bulk KK matter fields, and further generalizes to arbitrary $N$-point cases, enabling a systematic derivation of the corresponding gravitational amplitudes with consistent incorporation of KK matter fields at leading order.

    ↳ hep-thgr-qchep-phJHEP(2025)·1 citation
42. 42*

    Spectral functions at nonzero temperature

    V. P. Nair🇺🇸 · Robert D. Pisarski🇺🇸

    We present a straightforward derivation of the spectral representation of a scalar field at nonzero temperature, assuming that the field is relativistically invariant in vacuum. This form was first derived by Bros and Buchholz.

    ↳ hep-thhep-lathep-phPRD(2026)·4 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.