Tue·Aug 5, 2025Tuesday·August 5, 2025

1. 01*

   Re-optimization of a deep neural network model for electron-carbon scattering using new experimental data

   Beata E. Kowal🇵🇱 · Krzysztof M. Graczyk🇵🇱 · Artur M. Ankowski🇵🇱 · Rwik Dharmapal Banerjee🇵🇱 · Jose L. Bonilla🇵🇱 · Hemant Prasad🇵🇱 · Jan T. Sobczyk🇵🇱

   We present an updated deep neural network model for inclusive electron-carbon scattering. Using the bootstrap model [Phys.Rev.C 110 (2024) 2, 025501] as a prior, we incorporate recent experimental data, as well as older measurements in the deep inelastic scattering region, to derive a re-optimized posterior model. We examine the impact of these new inputs on model predictions and associated uncertainties. Finally, we evaluate the resulting cross-section predictions in the kinematic range relevant to the Hyper-Kamiokande and DUNE experiments.

   hep-phcs.LGnucl-exnucl-thPRC(2025)·0 citations
2. 02*

   Assessing the lattice QCD space diffusion coefficient and the thermalization time of charm quark by mean of D meson observables at LHC

   Maria Lucia Sambataro (1 and 2)🇮🇹 · Vincenzo Minissale (1 and 3)🇮🇹 · Salvatore Plumari (1 and 2)🇮🇹 · Vincenzo Greco (1 and 2) ((1) Department of Physics and Astronomy, University of Catania, Catania, Italy (2) INFN-Laboratori Nazionali del Sud, Catania, Italy, (3) INFN Sezione di Catania, Catania, Italy)🇮🇹

   A central goal in the study of heavy-flavour production is to determine the interaction strength between Heavy Quarks (HQs) and the Quark-Gluon Plasma (QGP), quantified by the spatial diffusion coefficient $D_s(T)$. Recent lattice QCD (lQCD) results with dynamical fermions suggest a remarkably low value of $2\pi T{D}_s\approx 1$ at $T=T_c$ for charm quarks - significantly lower than both quenched QCD estimates and most phenomenological models - which typically yield $2\pi T{D}_s\approx 3.5-5$. This discrepancy raises the question of whether such a small $D_s(T)$, corresponding to a thermalization time ${\tau }_{th}\approx 1-1.5$ fm/c, is compatible with experimental measurements of key observables like the nuclear modification factor $R_{AA}$, the elliptic and triangular flow coefficients $v_2$ and $v_3$ for D mesons. Using an event-by-event Langevin transport framework, we analyze several scenarios and highlight the pivotal role played by the momentum dependence of the drag coefficient $A(p)={\tau }_{th}^{-1}(p)$. Our findings show that a small $2\pi T{D}_s(p\to 0)\approx 1-2$ values can align with experimental data \emph{only} if a significant momentum dependence in ${\tau }_{th}(p)=1/A(p)$ is included, as predicted by T-matrix approaches, or by the extended Quasi-Particle Model (QPMp). In contrast, assuming a momentum-independent ${\tau }_{th}=M_c{D}_s^{\text{lQCD}}/T$, it fails to reproduce the observed phenomenology. Furthermore, a short thermalization time of ${\tau }_{th}\approx 1.5$ fm/c implies a loss of sensitivity of the final-state observables to the initial charm-quark momentum distribution up $p_T\approx M_c$, suggesting a possible universal behavior driven by a dynamical attractor.

   hep-phnucl-thPLB(2026)·14 citations
3. 03*

   Phenomenology of two-photon interaction at high energies: accessing dilute and high parton density of the photon structure

   G. Zardo Becker🇧🇷

   In this work, ${\gamma }^{(\ast )}{\gamma }^{(\ast )}$ interactions in electron-positron collisions are studied across both low- and high-energy regimes. The analysis includes contributions from the Vector Meson Dominance (VMD) model (via Reggeon exchange), the Quark Parton Model (via box diagrams), and the gluonic component (described using the dipole formalism), which becomes dominant at high energies. A key feature of the dipole picture is that a photon can fluctuate into a quark-antiquark ($q\bar{q}$) pair, forming a color dipole. The dipole-dipole cross section is modeled using two different prescriptions. We analyze the impact of these models on several key observables: the total cross section for real photons (${\sigma }^{\gamma \gamma }$), including heavy quark production $\gamma \gamma \to c\bar{c}X,b\bar{b}X$; for virtual photons (${\sigma }^{{\gamma }^{\ast }{\gamma }^{\ast }}$); and the photon structure function ($F_2^{\gamma }$). Both prescriptions express the dipole-dipole interaction in terms of the dipole-proton scattering amplitude, used in Deep Inelastic Scattering (DIS). This amplitude is obtained by solving the Balitsky-Kovchegov (BK) non-linear evolution equation, incorporating running coupling and various models that differ in their treatment of the transition between the dilute and saturation regimes. These approaches exhibit distinct behaviors in photon-photon interactions at high energies: while one prescription describes the photon as a smaller and denser system, the other treats it as a larger and more dilute configuration. Accordingly, they predict greater and lesser hadron production in the final state, respectively, at the energies of future colliders. These characteristics become more significant with increasing photon virtuality.

   hep-ph0 citations
4. 04*

   Screening Masses for Scalar and Pseudoscalar Mesons and their Diquark Partners: Insights from the Contact Interaction Model

   M. A. Ramírez-Garrido🇲🇽 · R. J. Hernández-Pinto🇲🇽 · I. M. Higuera-Angulo🇺🇸 · L. X. Gutiérrez-Guerrero🇲🇽

   In this study, we calculate the screening masses of forty spin-zero meson and diquark states composed of light, heavy and heavy-light quarks, within a symmetry-preserving framework based on Dyson-Schwinger equations and a vector $\times$ vector contact interaction. This effective interaction reproduces hadron static properties at $T=0$ MeV that are in close agreement with experimental data and results from more sophisticated interaction kernels. Our analysis reveals that, at temperatures above the critical temperature, the dressed quark masses of the lightest mesons converge toward their respective current quark masses. Our work extends this study up to $T=500$ MeV. Furthermore, we demonstrate that the screening masses of meson parity partners become degenerate above a characteristic temperature, a phenomenon that is likewise reflected in the thermal evolution of their associated Bethe-Salpeter amplitudes (BSAs), providing robust evidence for chiral symmetry restoration. A similar trend is observed for scalar and pseudoscalar diquarks, whose screening masses also converge at high temperatures. As a consequence, these diquarks shall contribute equally to the baryon screening masses in the high-temperature regime. Wherever results from other approaches are available, we perform direct comparisons and observe consistency with our findings.

   hep-phPRD(2025)·5 citations
5. 05*

   Detection of Dark Matter Axions via the Quantum Hall Effect in a Resonant Cavity

   Aiichi Iwazaki🇯🇵

   We propose a new method for detecting dark matter axions using a resonant cavity coupled with a quantum Hall system. When a small sample exhibiting quantum Hall effect is placed inside the cavity and the cavity is tuned to resonance, two-dimensional electrons absorb the amplified radiation, leading to a rise in the sample's temperature. By monitoring this temperature increase, the mass $m_a$ of the axion can be inferred. As an example, consider a GaAs sample with surface area $S=0.01{\text{cm}}^2$ and small thickness $d=1\mu \mathrm{m}$ and its heat capacity $C_s$ at temperature $T=20\mathrm{mK}$. Because the energy flux of the incoming radiation is $P_{ra}\sim 5.9\times 10^{-20}\text{W}(S/0.01{\text{cm}}^2)(g_{a\gamma \gamma }/10^{-14}{\text{GeV}}^{-1}{)}^2(\sigma /10^7\text{eV})(10^{-5}\text{mbox}eV/m_a{)}^3(B/15\text{T}{)}^2({\rho }_d/0.3\mathrm{GeVc}{\mathrm{m}}^{-3})$ at the resonance with electrical conductivity $\sigma$ of the cavity wall, the temperature increase is $P_{ra}{t}_{ob}/C_s\simeq 4.8\text{mbox}mK(t_{ob}/1\text{s})(g_{a\gamma \gamma }/10^{-14}{\text{GeV}}^{-1}{)}^2(20\text{mbox}mK/T{)}^3(10^{-5}\text{mbox}eV/m_a{)}^3(\sigma /10^7\text{eV})(1\mu \text{m}/d)(B/15\text{T}{)}^2$ with $1\text{T}=10^4$ Gauss where $t_{ob}=1$s is the observation time. It must be smaller than a time constant $\tau >1$s associated with the heat dissipation into thermal bath. Such a large time constant can be realized using superconducting nanowire lead and thin film pedestal supporting the sample dilution refrigerator. The temperature increase $\Delta T\sim 5$mK is detectable using quantum point contact thermometer.

   hep-ph1 citation
6. 06*

   Lepton Flavor Violating Higgs Decays in a Minimal Doublet Left-Right Symmetric Model with an Inverse Seesaw

   M. Zeleny-Mora🇲🇽 · R. Gaitán🇲🇽 · R. Martínez🇨🇴

   In this study, we analyse the lepton flavor violation (LFV) decays within the framework of the Doublet Left-Right Symmetric model (DLRSM), based on the gauge group SU\left(2\right)_{L}\otimes SU\left(2\right)_{R}\otimes U\left(1\right)_{B-L}. The model features an extended gauge and scalar sector, including a bidoublet and two doublets which induce new charged currents interactions. Spontaneous Symmetry Breaking (SSB) occurs in two stages, introducing a new scale associated with the vacuum expectation value (VEV) of the right-handed doublet v_{R} assumed to lie above the electroweak scale. Neutrino masses are generated via the inverse seesaw mechanism, allowing sizeable mixing between active and sterile neutrinos. We diagonalize the full neutrino mass matrix and express the mixing in terms of physical parameters. We compute the branching ratios for LFV Higgs decays as functions of the heavy neutrino mass scale. Our numerical analysis incorporates current experimental bounds and projected sensitivities, highlighting viable regions of parameter space where LFV signals could be observed at future colliders.

   hep-phEPJC(2026)·1 citation
7. 07*

   Implications of a dark grand unification

   Phung Van Dong🇻🇳 · Do Thi Huong🇻🇳

   Given that dark matter and normal matter are nontrivially unified in a grand unified theory, called dark grand unification, we derive novel residual theories at low energy explaining dark matter and neutrino mass. The first chain of which is $E_6\to SU(3{)}_C\otimes SU(3{)}_L\otimes SU(3{)}_R$, which contains a matter parity by itself stabilizing a dark matter candidate and producing neutrino mass via a seesaw. The second chain is $\mathrm{Trinification}\to SU(3{)}_C\otimes SU(3{)}_L\otimes U(1{)}_X\otimes U(1{)}_N$, which results in a novel family-universal 3-3-1-1 model, opposite to the normal 3-3-1-1 (or corresponding 3-3-1) model. Surprisingly, it is a variant of both minimal 3-3-1 model and 3-3-1 model with right-handed neutrinos since both $e_R$ and ${\nu }_R$ are located at the bottoms of lepton triplets. Since this universal 3-3-1-1 model is properly embedded in the trinification, the above matter parity works governing dark matter stability as well as suppressing unwanted fermion mixings. Further, neutrino masses are naturally generated by a canonical seesaw combined with a scotogenic scheme.

   hep-phhep-thJHEP(2025)·2 citations
8. 08*

   Boosting Sensitivity to $HH\to b\bar{b}\gamma \gamma$ with Graph Neural Networks and XGBoost

   Mohamed Belfkir🇦🇪 · Mohamed Amin Loualidi🇦🇪 · Salah Nasri🇦🇪

   In this paper, we explore the use of advanced machine learning (ML) techniques to enhance the sensitivity of double Higgs boson searches in the \( HH \to b\bar{b}\gamma\gamma \) decay channel at $\sqrt{s}=$ 13.6 TeV. Two ML models are implemented and compared: a tree-based classifier using XGBoost, and a geometrical-based graph neural network classifier (GNN). We show that the geometrical model outperform the traditional XGBoost classifier improving the expected 95\% CL upper limit on the double Higgs boson production cross-section by 28\%. Our results are compared to the latest ATLAS experiment results, showing significant improvement of both upper limit and Higgs boson self-coupling (${\kappa }_{\lambda }$) constraints.

   hep-phhep-exPTEP(2025)·3 citations
9. 09*

   Generalized parton distributions and gravitational form factors at large momentum transfer

   Yoshitaka Hatta🇺🇸 · Jakob Schoenleber🇺🇸

   Within the soft collinear effective theory (SCET), we derive a factorization theorem which resums Sudakov logarithms $({\alpha }_s{\ln }^2(-t){)}^n$ to all orders in the quark-in-quark generalized parton distribution (GPD) at large momentum transfer $t$, and perform a consistency check to one-loop. We show that the same Sudakov factor appears in the `Feynman' contribution to the GPDs of the nucleon. Our result enables the resummation of all the large logarithms $\ln Q^2$ and ${\ln }^{2}t$ in exclusive processes with two hard scales ${\Lambda }_{\mathrm{QCD}}^2\ll |t|\ll Q^2$. We also present a SCET power counting analysis of the Feynman contributions to the GPDs and show that the $x$-dependence of GPDs factorizes at large-$t$ with controlled corrections. This in particular implies that any ratio of GPD moments such as the electromagnetic and gravitational form factors (GFF) is perturbatively calculable in this approximation. Furthermore, we identify a novel order ${\alpha }_s$ power-law $t$-dependence in the GPD and the $D$-type GFF that will dominate over the standard order $({\alpha }_s^2)$ `leading twist' asymptotic contribution in the phenomenologically relevant region of $t$.

   hep-phJHEP(2025)·3 citations
10. 10*

    Light hadronic decays of spin-0 partner of $X(3872)$

    Hong-Shuo Gao🇨🇳 · Zu-Xin Cai🇨🇳 · Gang Li🇨🇳 · Shi-Dong Liu🇨🇳

    The $X(3872)$ is theoretically predicted to have a spin-0 partner state denoted as $X_0$. Assuming the $X_0$ as a $D\bar{D}$ molecular bound state, we calculate the decay widths of $X_0\to VV$ and $X_0\to PP$ ($V$ and $P$ stand for light vector and pseudoscalar mesons, respectively) via intermediate charmed meson loops. Three different configurations of the $X_0$, i.e., pure neutral components ($\theta =0$), isospin singlet ($\theta =\pi /4$) and pure charged components ($\theta =\pi /2$), are investigated. Within a commonly accepted range of the model parameter $\alpha$, the predicted decay widths of $X_0\to VV$ are on the order of a few hundred $\mathrm{keV}$, while the decay widths of $X_0\to PP$ can reach several $\mathrm{MeV}$. The $X_0\to \rho \rho$ and $\pi \pi$ have larger decay rates. The relative width ratios between the channels are nearly model-independent. Moreover, among those channels only with isovector or isoscalar mesons, the relevant ratios are also independent of the phase angle. The predicted ratios are helpful for searching the $X_0$ in the future experiments at BESIII and Belle II.

    hep-phChin.Phys.Lett.(2025)·3 citations
11. 11*

    Investigation of nonlinear dipole cross sections

    G.R.Boroun🇮🇷 · B.Rezaei🇮🇷

    The nonlinear corrections to the Golec-Biernat Wusthoff (GBW) and Bartels- Golec- Kowalski (BGK) models, as discussed by Peredo-Hentschinski [M.A.Peredo and M.Hentschinski, Phys.Rev.D{109}, 014032 (2024)], are analyzed in terms of the gluon density${}^{,}$s nonlinear behavior. We incorporate these nonlinear corrections into the low $x$ gluon distribution of the modified BGK model for electron-ion colliders. By verifying that these results allow for a more direct assessment of the relevance of nonlinear corrections in describing the dipole cross section of heavy nuclei, we determine the dipole cross section at a fixed $\sqrt{s}$ and $Q^2$ to the minimum value of $x$ given by $Q^2/s$ of the center-of-mass energy of electron-ion colliders. Additionally, we examine the nonlinear gluon density in the photoproduction cross sections of vector mesons $\Psi (2s)$ and $J/\Psi$ on a lead nucleus.

    hep-ph1 citation
12. 12*

    Plasma Dynamics in Higher-Derivative Electrodynamics: A Renormalised Two-Loop Framework

    Prabhat Singh🇮🇳 · Punit Kumar🇮🇳

    We present a finite-temperature study of Bopp-Podolsky electrodynamics, following electron-proton plasmas through one- and two-loop order with dimensional regularisation and hard-thermal-loop resummation. The higher-derivative operator is found to generate no new ultraviolet divergences; all counter-terms reduce to the single photon wave-function factor of ordinary QED. The static inter-particle force acquires a double-Yukawa profile, the familiar Debye term plus an opposite-signed contribution from the heavy Podolsky pole that removes the Coulomb singularity at sub-femtometre distances, providing an intrinsic ultraviolet completion of electrostatics. Gauge symmetry drives the transverse photon self-energy to zero at vanishing momentum, so no magnetic screening mass appears at any perturbative order. In a covariantly constant background the full two-loop sunset diagram yields a single, dimension-eight operator suppressed by T^2/M^2, implying permille-level shifts in thermodynamic quantities for realistic plasmas. The exact Debye mass and a leading-log calculation show the dc electrical conductivity exceeds its QED value by less than 10^-4. Conditions for observable Podolsky plasmons and cosmological constraints are identified, supplying precise benchmarks for future strong-field, collider and lattice investigations.

    hep-phphysics.plasm-ph0 citations
13. 13*

    Polarization analysis in $e^{+}{e}^{-}\to J/\psi \to$ baryon-antibaryon pairs

    Zhe Zhang🇨🇳 · Tianbo Liu🇨🇳 · Rong-Gang Ping🇨🇳 · Jiao Jiao Song🇨🇳 · Weihua Yang🇨🇳

    We present a comprehensive polarization analysis for the process $e^{+}{e}^{-}\to J/\psi \to$ baryon-antibaryon pairs~$B_1{\bar{B}}_2$. All possible helicity amplitudes for $e^{+}{e}^{-}\to J/\psi$ and $J/\psi \to B_1{\bar{B}}_2$ are provided, along with their transformation properties under parity and $CP$ operations. Taking full account of beam polarization, we analyze the polarization of the $J/\psi$ produced in $e^{+}{e}^{-}$ annihilation and show that all eight independent polarization components can be nonzero. By introducing a polarization transfer matrix, we propose a novel method to compute the polarization transfer in the decay $J/\psi \to B_1{\bar{B}}_2$. Considering both hadronic and radiative baryon decay models, we derive the joint angular distribution of the final-state particles. Focusing on the process $J/\psi \to \Lambda {\bar{\Sigma }}^0$, we provide statistical uncertainty estimates for probing $CP$ violation in associated production of different baryons. This work establishes a complete framework for studying the parity and $CP$ violations present in baryon productions and decays within the helicity formalism.

    hep-phPRD(2025)·6 citations
14. 14*

    Diffractive electroproduction of light vector particles: leading Fock-state contribution in the presence of significant higher Fock-state effects

    Chao Shi🇨🇳 · Liming Lu🇨🇳 · Jian-feng Li🇨🇳 · Wenbao Jia🇨🇳

    We study exclusive diffractive production of vector mesons and photon using the color dipole model with leading Fock state light front wave functions derived from Dyson Schwinger and Bethe Salpeter equations. New results for the $\varphi$ meson and real photon are presented. Without data fitting, our calculation well matches HERA data in certain kinematical domains. The key finding of this paper is that in a color dipole model study for $\rho /\gamma$ and $\varphi$, where light quarks are involved, the leading $q\bar{q}$ approximation is valid only when $Q^2$ exceeds $20$ and 10 GeV${}^2$ respectively, unlike $J/\psi$ which can be well described for $Q^2\approx 0$ GeV${}^2$. This underscores the special role of $\varphi$ electroproduction in color dipole picture: it strikes a balance between the large dipole size typical of light mesons and the smaller size associated with high $Q^2$ photons, making it potentially well suited for probing gluon saturation effects.

    hep-phPRD(2025)·1 citation
15. 15*

    Searches for new light particles at the Troitsk Meson Factory (TiMoFey)

    Sergey Demidov🇷🇺 · Alexander Feschenko🇷🇺 · Dmitry Gorbunov🇷🇺 · Alexander Izmaylov🇷🇺 · Dmitry Kalashnikov🇷🇺 · Leonid Kravchuk🇷🇺 · Ekaterina Kriukova🇷🇺 · Yury Kudenko🇷🇺 · Nikita Mashin🇷🇺 · Yury Senichev🇷🇺

    The project of a new accelerator complex at the Institute for Nuclear Research of RAS in Troitsk has recently been included in the Russian National Program ``Fundamental Properties of Matter". It will sustain a proton beam with a current of 300 (100) $\mu$A and a proton kinetic energy of $T_p=423(1300)$ MeV at the first (second) stage of operation. The complex is multidisciplinary, and here we investigate its prospects in exploring new physics with light, feebly interacting particles. We find that TiMoFey can access new regions of parameter space of models with light axion-like particles and models with hidden photons, provided by a generic multipurpose detector installed downstream the proton beam dump. The signature to be exploited is the decay of a new particle into a pair of known particles inside the detector. Likewise, TiMoFey can probe previously unreachable ranges of parameters of models with millicharged particles obtained in measurements with detectors recognizing energy deposits associated with elastic scattering of new particles, passing through the detector volume. The latter detector may be useful for dark matter searches, as well as for studies of neutrino physics suggested at the facility in the Program framework.

    hep-phhep-ex3 citations
16. 16*

    Revisiting Polynomial Hybrid Inflation: Planck and ACT Compatibility via Radiative Corrections

    Waqas Ahmed🇨🇳 · Saleh O. Allehabi🇸🇦 · Mansoor Ur Rehman🇸🇦

    We investigate the impact of one-loop radiative corrections in a non-supersymmetric model of hybrid inflation with a chaotic (polynomial-like) potential,$V(\varphi )=V_0+{\lambda }_p{\varphi }^p$, in the light of the latest constraints from \textit{Planck} and \textit{Atacama Cosmology Telescope} (ACT) observations. Here, $V_0$ denotes the energy scale of inflation, and ${\lambda }_p$ is a coupling associated with the polynomial term of power $p$. These corrections can naturally arise from couplings of the inflaton to other matter fields, which also facilitate the reheating process. At the tree level, the predictions of such models for the scalar spectral index $n_s$ and the tensor-to-scalar ratio $r$ typically lie outside the current observational bounds. However, incorporating one-loop radiative corrections modifies the potential to, \[ V(\phi) = V_0 + \lambda_p \phi^p + A \phi^4 \ln (\phi/ \mu), \] where $A$ characterizes the strength of the inflaton's coupling to other fields, and \(\mu\) is an appropriate renormalization scale. This radiatively corrected potential can reconcile the model with the combined \textit{Planck}+ACT data over a suitable range of parameter space explored in this work. In particular, radiative corrections from fermionic loops ($A<0$) suppress the tensor-to-scalar ratio $r$, while simultaneously yielding a red-tilted spectrum with $n_s<1$, even for sub-Planckian field excursions. This brings the prediction in line with current observations, while still allowing for potentially detectable signatures of primordial gravitational waves. Furthermore, the inflaton's couplings enable successful reheating and naturally accommodate non-thermal leptogenesis, providing a unified framework for inflation and baryogenesis.

    hep-phastro-ph.COgr-qchep-thPRD(2026)·11 citations
17. 17*

    Direct Evaluation of CP Phase of CKM matrix, General Perturbative Expansion and Relations with Unitarity Triangles

    Masaki J. S. Yang🇯🇵

    In this letter, using a rephasing invariant formula $\delta =\arg [V_{ud}{V}_{us}{V}_{cb}{V}_{tb}/V_{ub}\det V_{\mathrm{CKM}}]$, we evaluate the CP phase $\delta$ of the CKM matrix $V_{\mathrm{CKM}}$ perturbatively for small quark mixing angles $s_{ij}^{u,d}$ with associated phases ${\rho }_{ij}^{u,d}$. Consequently, we derived a relation $\delta \simeq \arg [\Delta s_{12}\Delta s_{23}/(\Delta s_{13}-s_{12}^u{e}^{-i{\rho }_{12}^u}\Delta s_{23})]$ with $\Delta s_{ij}\equiv s_{ij}^d{e}^{-i{\rho }_{ij}^d}-s_{ij}^u{e}^{-i{\rho }_{ij}^u}$. Such a result represents the analytic behavior of the CKM phase. The uncertainty in the relation is of order $O({\lambda }^2)\sim 4\%$, which is comparable to the current experimental precision. Comparisons with experimental data suggest that the hypothesis of some CP phases being maximal. We also discussed relationships between the phase $\delta$ and unitarity triangles. As a result, several relations between the angles $\alpha ,\beta ,\gamma$ and $\delta$ are identified through other invariants $V_{il}{V}_{jm}{V}_{kn}/\det V_{\mathrm{CKM}}$.

    hep-ph11 citations
18. 18*

    Nucleon mass in covariant baryon chiral perturbation theory at leading two-loop order

    Ze-Rui Liang🇨🇳 · Han-Xue Chen🇨🇳 · Feng-Kun Guo🇨🇳 · Zhi-Hui Guo🇨🇳 · De-Liang Yao🇨🇳

    We calculate the nucleon mass within a manifestly relativistic formulation of baryon chiral perturbation theory (BChPT), extending the framework to leading two-loop order ($\mathcal{O}(p^5)$). By employing dimensional counting analysis and rigorously verifying the extended on-mass-shell scheme at this order, we obtain a complete chiral representation of the nucleon mass that preserves analyticity, respects proper power counting, and maintains renormalization-scale independence. The resulting expression exhibits excellent convergence, with $\mathcal{O}(p^5)$ contributions remaining small ($\sim 8\mathrm{MeV}$). This formulation provides a robust foundation for chiral extrapolation, demonstrating remarkable agreement with lattice QCD data across a wide range of pion masses ($M_{\pi }\lesssim 300\mathrm{MeV}$). The success of this calculation establishes two-loop relativistic BChPT as a precision tool for studying nucleon structure and related properties.

    hep-phhep-latPoS(2026)·0 citations
19. 19*

    Gravitational form factors of the nucleon from the chiral effective model

    Daisuke Fujii🇯🇵 · Mamiya Kawaguchi🇨🇳 · Mitsuru Tanaka🇯🇵

    We investigate the confining pressure and associated global property, i.e, D-term, of the nucleon using the skyrmion approach formulated within scale-invariant chiral perturbation theory. In this framework, the nucleon is modeled as a skyrmion, and a scalar meson is introduced to incorporate the effects of the scale anomaly via low-energy theorems. The contributions from the current quark mass and gluonic dynamics to the scale anomaly are encoded through the pion and scalar meson masses, respectively. By decomposing the nucleon's energy-momentum tensor, we isolate the anomalous components and analyze their role in generating pressure. We find that the gluonic contribution to the scale anomaly plays a dominant role in producing confining pressure. In comparison with results from conventional chiral perturbation theory in the chiral limit, the total pressure derived from sChPT provides improved qualitative agreement with lattice QCD results. We also evaluate the D-term and compare it with recent lattice and model-independent determinations.

    hep-phhep-thnucl-thPoS(2026)·0 citations
20. 20*

    Columbia plot based on symmetry-improved CJT formalism in linear sigma model

    Yuepeng Guan🇨🇳 · Mamiya Kawaguchi🇨🇳 · Shinya Matsuzaki🇨🇳 · Akio Tomiya🇯🇵

    We study the Columbia plot for the chiral phase transition in the framework of a three-flavor linear sigma model based on the Cornwall-Jackiw-Tomboulis (CJT) formalism. The conventional CJT approach with the Hartree truncation suffers from artificial chiral breaking, leading to the violation of the Nambu-Goldstone theorem and the (anomalous) chiral Ward-Takahashi identities. We apply the symmetry-improved CJT formalism to resolve this issue. We observe a first-order phase transition and a tricritical point in the light-quark mass regime, which is fairly insensitive to the size of the sigma meson, in contrast to the conventional CJT approach. The tricritical point, found on the $m_s$ axis, is at $m_s^{\mathrm{tri}}/m_s^{phys.}=0.175$ with $m_s^{phys.}$ being the physical strange quark mass in real-life QCD. The critical pion mass in the three-flavor symmetric limit, on the second-order boundary, is measured at $m_{\pi }\sim 52.4$ MeV, with the critical temperature $T_c\sim 51.7$ MeV.

    hep-phPRD(2026)·2 citations
21. 21*

    Jet-mass in V/H+jet up to four-loops with $k_t$ clustering

    K. Khelifa-Kerfa🇩🇿 · M. Benghanem🇸🇦

    We extend the work of [1] to the case in which final-state jets, produced in association with a Higgs or vector boson, are defined using the $k_t$ algorithm. We thereby compute the full distribution of the invariant mass squared of the leading, highest-$p_t$ jet, including both clustering and non-global logarithms, up to four-loops in perturbation theory. Our results are derived within the eikonal approximation under the assumption of strong ordering in the momenta of the final-state partons, and are consequently valid up to single-logarithmic accuracy. The final semi-analytical expressions retain the complete dependence on both colour and the jet radius. The broad features of $k_t$ clustering observed in $e^{+}{e}^{-}$ processes persist in hadronic collisions, together with novel characteristics that are absent in the $e^{+}{e}^{-}$ environment.

    hep-phhep-thJHEP(2026)·2 citations
22. 22*

    Electroweak loop corrections to $gg\to gH$ at the LHC

    Huan-Yu Bi🇨🇳 · Yan-Qing Ma🇨🇳 · Dao-Ming Mu🇨🇳

    We present the results of the complete electroweak loop corrections to the process $gg\to gH$ at the Large Hadron Collider. The electroweak corrections to the total cross section are found to be approximately $+4\%$. At the differential level, the corrections exceed $+4\%$ in the low Higgs transverse momentum region and fall below $-4\%$ in the high transverse momentum region, leading to a noticeable shape distortion for this distribution. Our results represent a necessary step towards to complete next-to-leading order electroweak correction of the Higgs + jet process.

    hep-phJHEP(2026)·5 citations
23. 23*

    Quark mass corrections in di-Higgs production amplitude at high-energy

    Sebastian Jaskiewicz🇨🇭

    A large theoretical uncertainty due to the choice of the top-quark mass renormalisation scheme is present in QCD predictions for Higgs boson pair production. In these proceedings, we report on the recent progress in tackling these uncertainties for the $gg\to HH$ amplitude in the high-energy limit $s,|t|,|u|\gg m_t^2\gg m_H^2$. Using the Method of Regions and Soft-Collinear Effective Theory, the leading power in $m_t$ behaviour of the amplitude is understood to all orders in the strong coupling expansion, and leading logarithmic resummation leads to a significant reduction in the scheme choice uncertainty in the virtual amplitude for di-Higgs production at high energies.

    hep-ph0 citations
24. 24*

    Impact of Non-Thermal Leptogenesis with Early Matter Domination on Gravitational Waves from First-order Phase Transition

    Dilip Kumar Ghosh🇮🇳 · Anish Ghoshal🇵🇱 · Koustav Mukherjee🇮🇳 · Nimmala Narendra🇮🇳 · Nobuchika Okada🇺🇸

    We study the impact of non-thermal leptogenesis on the spectrum of gravitational waves (GWs) produced by a strong first-order phase transition in the early Universe. We consider a scenario in which a heavy scalar field, $\varphi$, dominates the energy density of the early Universe and decays into heavy right-handed neutrinos (RHNs). The subsequent decay of RHNs generates a lepton asymmetry, which is partially converted into the observed baryon asymmetry via the sphaleron process. The $\varphi$-dominated era and the entropy injection from the decays of $\varphi$ and RHNs leave characteristic imprints on the GW spectrum, such as damping and modified frequency dependence, that distinguish it from the standard cosmological evolution. We identify the parameter space in which non-thermal leptogenesis is successful, leading to distinctive GW spectral features. We show that these GW signals can fall within the sensitivity ranges of future detectors such as ET, DECIGO and BBO. If observed, they would provide valuable insights into the thermal history and dynamics of the early Universe.

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

    Nuclear modification factor $I_{AA}$ in $AA$ collisions at RHIC and LHC energies in scenarios with and without quark-gluon plasma formation in $pp$ collisions

    B.G. Zakharov🇷🇺

    We calculate the away-side hadron-triggered modification factor $I_{AA}$ in $AA$ collisions at RHIC and LHC energies for scenarios with and without quark-gluon plasma formation in $pp$ collision. We find that for both scenarios theoretical results for $I_{AA}$ agree well with the available data for 2.76 TeV Pb+Pb and 0.2 TeV Au+Au collisions. We make predictions for $I_{AA}$ in 7 TeV O+O collisions that are planned at the LHC. Our results show that measuring $I_{OO}$ in the whole centrality interval and at small centrality ($\lesssim 5$%) may give information on the presence of jet quenching in $pp$ collisions.

    hep-phnucl-thJETP Lett.(2025)·0 citations
26. 26*

    Lepton parity dark matter and naturally unstable domain walls

    Ernest Ma🇺🇸 · Partha Kumar Paul🇮🇳 · Narendra Sahu🇮🇳

    We propose a simple and predictive setup that connects neutrino masses, dark matter (DM), and gravitational waves. A minimal lepton parity DM scenario is considered where the residual symmetry $(-1{)}^L$ from the type I seesaw acts as the dark parity $D=(-1{)}^{L+2j}$, ensuring DM stability without imposing any new symmetry. A singlet Majorana fermion $S$ with even lepton parity serves as the DM candidate, interacting via a real scalar $\sigma$ which is also even lepton parity. The scalar potential possesses an accidental ${\mathcal{Z}}_2$ symmetry, whose spontaneous breaking gives rise to unstable domain walls (DW) in the presence of explicit ${\mathcal{Z}}_2$ breaking terms allowed by the lepton parity. The subsequent DW annihilation generates a stochastic gravitational wave (GW) background potentially observable at different GW experiments.

    hep-phastro-ph.COPRD(2025)·6 citations
27. 27*

    Goofy transformations and the hierarchy problem

    Andreas Trautner🇵🇹

    Goofy transformations of the Standard Model (SM) Higgs field generally prohibit its bare mass term. This opens up an entirely new class of solutions to the electroweak (EW) hierarchy problem. We argue that these can be intrinsically linked to the flavor structure and origin of CP violation.

    hep-phPLB(2026)·8 citations
28. 28*

    Functional renormalization group study of rho condensate at a finite isospin chemical potential in the quark meson model

    Mohammed Osman🇨🇳 · Defu Hou🇨🇳 · Wentao Wang🇨🇳 · Hui Zhang🇨🇳

    We investigate the effect of an isospin chemical potential (${\mu }_I$) within the quark-meson model, which approximates quantum chromodynamics (QCD) by modeling low energy phenomena such as chiral symmetry breaking and phase structure under varying conditions of temperature and chemical potential. Using the functional renormalization group (FRG) flow equations, we calculate the phase diagram in the chiral limit within the two-flavor quark-meson model in a finite ${\mu }_I$ with $\rho$ vector meson interactions. Fluctuation effects significantly decrease the critical chemical potential from the mean-field (MF) value ${\mu }_{I,MF}>m_{\rho }$ to lower value, at which point the $\rho$ vector meson condensates alongside the chiral condensate once the isospin chemical potential exceeds the critical value ${\mu }_I^{\text{crit}}$. This $\rho$ condensation is investigated numerically for different meson coupling strengths. The $\rho$ meson dominated region is delineated from other phases by a second-order phase transition at lower ${\mu }_I$ and a first-order transition at slightly higher ${\mu }_I$.

    hep-phCPC(2026)·0 citations
29. 29*

    On the Standard Model Mass Spectrum and Interactions In the Holomorphic Unified Field Theory

    J. W. Moffat🇨🇦 · E. J. Thompson🇨🇦

    We present a unified, ultraviolet-finite framework for the full Standard Model particle mass spectrum based on the Holomorphic Unified Field Theory augmented by nonlocal entire-function regulators. Starting from a single holomorphic action on the complexified spacetime manifold \( M^4_{\mathbb{C}} \), with a Hermitian metric unifying gravity, gauge, and matter sectors, we embed exponential regulator insertions to render all loop integrals finite without breaking gauge or diffeomorphism invariance. After spontaneous breaking of the electroweak and grand unified symmetries, analytic expressions for the charged lepton, quark, and neutrino mass matrices are derived in terms of holomorphic Yukawa textures and regulator form factors. A minimal Froggatt-Nielsen flavon sector fixes all \( \mathcal{O}(1) \) coefficients in terms of two continuous inputs. Regulator-suppressed one- and two-loop renormalization group evolution then yields predictions for all fermion masses, CKM and PMNS mixing angles, \( W \) and \( Z \) boson masses, and the Higgs boson mass and self-couplings. Finally, under a mild set of geometric and topological assumptions we show that gauge coupling unification, three chiral families, hypercharge quantization, and the shape of the Higgs potential are genuine predictions of the holomorphic nonlocal framework.

    hep-phEur.Phys.J.Plus(2026)·7 citations
30. 30*

    Leptophilic dark matter in $U(1{)}_{L_i-L_j}$ models: a solution to the Fermi-LAT Galactic Center Excess consistent with cosmological and laboratory observations

    Jordan Koechler🇮🇹 · Mattia Di Mauro🇮🇹

    The particle origin of dark matter (DM) remains elusive despite decades of direct, indirect, and collider searches. Several groups have reported a $\gamma$-ray excess toward the Galactic Centre, commonly referred to as the Galactic Centre Excess (GCE). Its spectrum is consistent with annihilation of weakly interacting massive particles (WIMPs) of mass $\mathcal{O}(10-100)$ GeV and a thermal-relic cross section. Although many concrete WIMP models reproduce the GCE spectrum, most are now excluded by direct detection experiments that are approaching the neutrino floor. We investigate a class of anomaly-free extensions of the Standard Model featuring gauged differences of lepton number, $U(1{)}_{L_i-L_j}$, and gauged baryon minus lepton number, $U(1{)}_{B-L}$. We show that these models can reproduce the GCE while remaining compatible with the observed relic abundance. We then impose collider and direct detection constraints, accounting for both tree-level and loop-induced kinetic mixing. The $L_{\mu }-L_e$ model gives the best fit to the GCE: a DM mass of $m_{\chi }\sim 40-50$ GeV remains consistent with the muon and electron magnetic moment anomalies, $(g-2{)}_{\mu ,e}$, as well as current collider and direct detection limits, for mediator masses in the range $m_{A^{\prime }}\sim 70-86$ GeV and a DM-mediator coupling of $(1-5)\times 10^{-2}$. By contrast, the $L_e-L_{\tau }$ and $L_{\mu }-L_{\tau }$ models yield poorer fits; satisfying both the relic density and experimental bounds forces the DM mass to lie very close to resonance (i.e., approximately half the mediator mass). Finally, while the $B-L$ model also matches the GCE well, its parameter space is almost entirely ruled out by strong direct detection limits, except for the narrow resonance region where $m_{\chi }$ should be equal to $m_{A^{\prime }}/2$ requiring a fine-tuning at the few-percent level.

    hep-phastro-ph.COastro-ph.HEPRD(2025)·15 citations
31. 31*

    QCD corrections to Minimal Dark Matter annihilations

    Alessandro Strumia🇮🇹

    QCD corrections to fermionic Minimal Dark Matter annihilations increase its annihilation cross section (by 2% for a weak doublet, 1.3% for a triplet, 0.5% for a quintuplet) and thereby the Dark Matter mass required to achieve the observed cosmological relic abundance via thermal freeze-out.

    hep-phastro-ph.COJHEP(2025)·1 citation
32. 32*

    Criticality analysis of nuclear binding energy neural networks

    S.A. Sundberg · R.J. Furnstahl🇺🇸

    Machine learning methods, in particular deep learning methods such as artificial neural networks (ANNs) with many layers, have become widespread and useful tools in nuclear physics. However, these ANNs are typically treated as ``black boxes'', with their architecture (width, depth, and weight/bias initialization) and the training algorithm and parameters chosen empirically by optimizing learning based on limited exploration. We test a non-empirical approach to understanding and optimizing nuclear physics ANNs by adapting a criticality analysis based on renormalization group flows in terms of the hyperparameters for weight/bias initialization, training rates, and the ratio of depth to width. This treatment utilizes the statistical properties of neural network initialization to find a generating functional for network outputs at any layer, allowing for a path integral formulation of the ANN outputs as a Euclidean statistical field theory. We use a prototypical example to test the applicability of this approach: a simple ANN for nuclear binding energies. We find that with training using a stochastic gradient descent optimizer, the predicted criticality behavior is realized, and optimal performance is found with critical tuning. However, the use of an adaptive learning algorithm leads to somewhat superior results without concern for tuning and thus obscures the analysis. Nevertheless, the criticality analysis offers a way to look within the black box of ANNs, which is a first step towards potential improvements in network performance beyond using adaptive optimizers.

    ↳ nucl-thhep-phJ.Phys.G(2025)·2 citations
33. 33*

    Resolving the Planck-DESI tension by nonminimally coupled quintessence

    Jia-Qi Wang🇨🇳 · Rong-Gen Cai🇨🇳 · Zong-Kuan Guo🇨🇳 · Shao-Jiang Wang🇨🇳

    The Planck measurement of the cosmic microwave background (CMB) has established the $\Lambda$-cold-dark-matter ($\Lambda$CDM) model as the concordant model along with other observations. However, recent measurements of baryon acoustic oscillations (BAO) from the Dark Energy Spectroscopic Instrument (DESI) have renewed the matter fraction ${\Omega }_{\mathrm{m}}$ tension between Planck-$\Lambda$CDM and DESI-$\Lambda$CDM. Directly reconciling this CMB-BAO tension with a dynamical DE in Chevallier-Polarski-Linder (CPL) parametrization seems to imply a crossing of the equation-of-state (EOS) through $w=-1$ at low redshifts. In this paper, we resolve this ${\Omega }_{\mathrm{m}}$ tension by allowing for the DM nonminimally coupled to gravity via a quintessence field. This non-minimal coupling is preferred over $3\sigma$ confidence level. Consequently, even though the usual effective EOS of the coupled quintessence apart from the standard CDM part never crosses but always is above $w=-1$, a misidentification with the $w_0{w}_a$CDM model would exactly fake such a crossing behavior, and the tensions on neutrino mass and growth rate in the $\Lambda$CDM model are also relieved in our model as a result of the resolved ${\Omega }_{\mathrm{m}}$ tension.

    ↳ astro-ph.COhep-phPRD(2026)·73 citations
34. 34*

    Clustering of Primordial Black Holes in Excursion Set Theory

    Hamed Kameli🇮🇷 · Encieh Erfani🇨🇦

    We investigate the clustering of Primordial Black Holes (PBHs) within the framework of Excursion Set Theory (EST). The EST formalism is extended to compute the joint probability of forming PBH pairs within a clustering distance, based on two stochastic trajectories with a shared history. Our results show that an enhanced power spectrum not only increases the formation of PBHs in specific mass ranges but also enhances their clustering probability. We find a one-to-one correspondence between the blue-tilted spectral index and the mass ranges in which PBHs form and cluster. Additionally, we demonstrate that the clustering probability decreases asymptotically with increasing clustering distance, while a higher critical density threshold (barrier) leads to a suppression of clustering abundance.

    ↳ astro-ph.COhep-ph3 citations
35. 35*

    Lattice Calculation of Short-Range Contributions to Neutrinoless Double-Beta Decay ${\pi }^{-}\to {\pi }^{+}ee$ at Physical Pion Mass

    Peter Boyle🇺🇸 · Felix Erben🇨🇭 · Xu Feng🇨🇳 · Jonathan M. Flynn🇬🇧 · Nicolas Garron🇬🇧 · Taku Izubuchi🇺🇸 · Luchang Jin🇺🇸 · Rajnandini Mukherjee🇬🇧 · J. Tobias Tsang🇨🇭 · Xin-Yu Tuo🇺🇸

    Neutrinoless double-beta ($0\nu \beta \beta$) decays provide an excellent probe for determining whether neutrinos are Dirac or Majorana fermions. The short-range matrix elements associated with the ${\pi }^{-}\to {\pi }^{+}ee$ process contribute at leading order in the $0\nu \beta \beta$ decay channel $nn\to ppee$ through pion exchange between nucleons. However, current lattice calculations show notable discrepancies in predicting these short-range contributions. To address this issue, we perform a lattice QCD calculation of the ${\pi }^{-}\to {\pi }^{+}ee$ matrix elements using domain wall fermion ensembles at the physical pion mass generated by the RBC and UKQCD Collaborations. To mitigate contamination from around-the-world effects, we develop a new method to reconstruct and subtract them directly from lattice data. We then perform a nonperturbative renormalization using the RI/SMOM scheme. Compared with previous studies, this work reduces the uncertainties in the matrix elements and provides an independent cross-check that helps to reconcile the discrepancies among previous lattice calculations.

    ↳ hep-lathep-phnucl-thPRD(2026)·1 citation
36. 36*

    $\nu p$-process in Core-Collapse Supernovae: Imprints of General Relativistic Effects

    Alexander Friedland🇺🇸 · Derek J. Li🇺🇸 · Giuseppe Lucente🇺🇸 · Ian Padilla-Gay🇺🇸 · Amol V. Patwardhan🇺🇸

    The origin of a number of proton-rich isotopes in the solar system has been a long-standing puzzle. A promising explanation is the $\nu p$-process, which is posited to operate in the neutrino-driven outflows that form inside core-collapse supernovae after shock revival. While recent studies have analyzed several relevant physical effects that influence the efficiency of this process, the impact of General Relativity (GR) on it remains unexplored. We perform a comparative analysis of the time-integrated $\nu p$-process yields in Newtonian and fully GR calculations, using detailed models of time-evolving outflow profiles. The GR effects are seen to suppress the production of seed nuclei, significantly boosting the resulting $p$-nuclide abundances. Our reference GR model, with an 18~$M_{\odot }$ progenitor, reproduces both the relative and absolute solar system abundances of the entire set of the $p$ nuclides in the mass range $74\le A\le 102$. The yields are suboptimal in our 12.75~$M_{\odot }$ GR model, where the outflow transitions to the supersonic regime several seconds into the explosion, suppressing further $p$-nuclide production. In both models, most of the production of the crucial ${}^{92,94}\mathrm{Mo}$ and ${}^{96,98}\mathrm{Ru}$ $p$ isotopes occurs relatively early, 1--3 seconds after shock revival. In contrast, a large fraction of the shielded isotope ${}^{92}\mathrm{Nb}$ is produced in the subsequent ejecta. The impact of GR on this isotope is especially large, with its final abundance boosted by a factor of 25 compared to a Newtonian calculation. In summary, with the GR effects taken into account, the $\nu p$-process in a sufficiently massive progenitor can provide a unifying explanation for the origin of all $p$ nuclei in the solar system up to ${}^{102}$Pd.

    ↳ astro-ph.HEhep-phnucl-thJCAP(2026)·3 citations
37. 37*

    Wiener filtering and multi-tracer techniques for dark matter cross-correlations between gamma-ray emission and galaxy catalogs

    Andrea Rubiola🇮🇹 · Stefano Camera🇮🇹 · Nicolao Fornengo🇮🇹

    Cross-correlations between a gravitational tracer of dark matter and the contribution to the unresolved gamma-ray background (UGRB) from the radiation produced by the annihilation of the particles responsible for the dark matter, have been established as a powerful tool to investigate the particle physics nature of dark matter. Cross-correlations of the UGRB with galaxy catalogs, cluster catalogs and weak lensing have indeed been measured. In this paper we study statistical techniques that could improve the sensitivity of the cross-correlation techniques on the bounds that can be set to the particle dark matter physical properties. The two methods that we investigate are the application of a Wiener filter and the exploitation of the full multi-tracer information. After identifying the optimal strategies, we show that the adoption of a Wiener filter in the cross-correlation analysis can improve the sensitivity to the dark matter annihilation rate by a factor of 2/2.5 as compared to the standard analysis where no filter is applied. The inclusion of the full multi-tracer information can improve the sensitivity up to a factor of 5 for dark matter masses below about 50 GeV, the Wiener filter remaining the best option for heavier dark matter.

    ↳ astro-ph.COhep-phJCAP(2025)·1 citation
38. 38*

    Tribute to Toshimitsu Yamazaki (1934-2025): Quest for Exotic Hadronic Matter

    Avraham Gal🇮🇱

    In this talk I pay tribute to Toshimitsu Yamazaki who died earlier this year. Yamazaki's leading contributions to Hadronic Physics, in particular to Strangeness Nuclear Physics in Japan and elsewhere, are well known. Two of the five Recurring Themes of his research, as listed in the Japan Academy site, are highlighted here: (i) Discovery of deeply bound pionic-atom states, and (ii) Search for kaonic nuclei -- Kaonic Proton Matter (KPM). I conclude by reviewing briefly my own recent work, confirming Farrar's conjecture that a deeply bound $H$ dibaryon is not ruled out by the weak-decay observation of $\Lambda \Lambda$ hypernuclei. However, the relatively long lifetime of such a deeply bound $H$ is much too short to qualify it for a Dark-Matter candidate.

    ↳ nucl-thhep-phnucl-exPoS(2026)·0 citations
39. 39*

    Comparing Generative Models with the New Physics Learning Machine

    Samuele Grossi🇮🇹 · Marco Letizia🇮🇹 · Riccardo Torre🇮🇹

    The rise of generative models for scientific research calls for the development of new methods to evaluate their fidelity. A natural framework for addressing this problem is two-sample hypothesis testing, namely the task of determining whether two data sets are drawn from the same distribution. In large-scale and high-dimensional regimes, machine learning offers a set of tools to push beyond the limitations of standard statistical techniques. In this work, we put this claim to the test by comparing a recent proposal from the high-energy physics literature, the New Physics Learning Machine, to perform a classification-based two-sample test against a number of alternative approaches, following the framework presented in Grossi et al. (2025). We highlight the efficiency tradeoffs of the method and the computational costs that come from adopting learning-based approaches. Finally, we discuss the advantages of the different methods for different use cases.

    ↳ stat.MLcs.LGhep-exhep-phNPB(2026)·6 citations
40. 40*

    Energy flow and radiation efficiency in radiative GRMHD simulations of neutron star ultraluminous X-ray sources

    Fatemeh Kayanikhoo🇵🇱 · Włodek Kluźniak · David Abarca · Miljenko Cemeljic🇨🇿

    We investigate numerically the energy flow and radiation efficiency of accreting neutron stars as potential ultraluminous X-ray sources (ULXs). We perform ten simulations {in radiative general relativistic magnetohydrodynamics (GRRMHD)}, exploring six different magnetic dipole strengths ranging from 10 to 100 GigaGauss, along with three accretion rates, 100, 300, and 1000 Eddington luminosity units. Our results show that the energy efficiency in simulations with a strong magnetic dipole of 100 GigaGauss is approximately half that of simulations with a magnetic dipole an order of magnitude weaker. Consequently, radiation efficiency is lower in simulations with stronger magnetic dipoles. We also demonstrate that outflow power increases as the magnetic dipole weakens, resulting in stronger beaming in simulations with weaker magnetic dipoles. As a result of beaming, simulations with magnetic dipole strengths below 30 GigaGauss exhibit apparent luminosities consistent with those observed in ULXs. As for the accretion rates, we find that higher accretion rates lead to more powerful outflows, higher kinetic efficiency, and lower radiation efficiency compared to those of lower accretion rate simulations.

    ↳ astro-ph.HEhep-phApJ(2025)·2 citations
41. 41*

    Density functional theory of renormalization group in nuclear matter

    Yong-rui Chen🇨🇳 · Wei-jie Fu🇨🇳 · Yang-yang Tan🇨🇳

    The density functional renormalization group (density-fRG) is proposed to investigate the density fluctuations within the functional renormalization group approach, which allows us to quantify the medium effect and study physics of high densities. This method is applied to the nucleon-meson effective field theory, also known as the Walecka model, to study the properties of nuclear matter at high baryon densities. It is found that both the attractive and repulsive nucleon meson interactions are screened by the high density medium, which results in a stiffer equation of state (EoS) of nuclear matter in the regime of ${\rho }_0\lesssim \rho \lesssim 2.5{\rho }_0$, then a softer EoS when $\rho \gtrsim 2.5{\rho }_0$. Here ${\rho }_0$ denotes the saturation baryon density of symmetric nuclear matter. Furthermore, a new phenomenon called the locking of Fermi surface is found. In the locking of Fermi surface the effective energy of quasi-nucleon is always close to the Fermi surface, which are both running with the renormalization group scale.

    ↳ nucl-thhep-phPRC(2026)·2 citations
42. 42*

    PSR J0614-3329: A NICER case for Strange Quark Stars

    Swarnim Shirke🇮🇳 · Rajesh Maiti🇮🇳 · Debarati Chatterjee🇮🇳

    Precise measurements of neutron star masses and radii by the NICER mission impose important constraints on the nuclear equation of state. The most recent NICER measurement of PSR J0614-3329 reported an equatorial radius of $R_{eq}=10.29_{-0.86}^{+1.01}$ km for a mass of $M=1.44_{-0.07}^{+0.06}{M}_{\odot }$. Considering all the NICER measurements to date, we find substantial evidence using Bayesian hypothesis ranking for strange quark stars over physically motivated models of neutron stars compatible with this low radius. This provides a strong case for quark matter in neutron stars and also for the possible existence of strange quark stars, a consequence of the Bodmer-Witten hypothesis, suggesting that they could be considered among the population of compact stars during analyses of astrophysical data. Using a wide sample of equations of state, we report the nucleonic equations of state that best fit current observations and rule out one model of strange quark matter.

    ↳ astro-ph.HEastro-ph.SRhep-phnucl-th11 citations
43. 43*

    Love beyond Einstein: Metric reconstruction and Love number in quadratic gravity using WEFT

    Arpan Bhattacharyya🇮🇳 · Saptaswa Ghosh🇮🇳 · Naman Kumar🇮🇳 · Shailesh Kumar🇮🇳 · Sounak Pal🇮🇳

    We study tidal Love numbers of static black holes in four-dimensional quadratic theory of gravity, extending the result of GR. We use worldline effective field theory (WEFT) methods to compute metric perturbations from one-point functions, treating the higher-derivative terms perturbatively. We show that insertions of scalar fields on the worldline induce non-zero tidal tails, and the corresponding Love number displays no RG running. The same conclusion holds for the insertions of tensor fields. Furthermore, for scalar dipole perturbations, we derive a Yukawa-deformed Frobenius solution and match the asymptotic behavior to fix the UV charge, finding agreement with EFT predictions of Wilson coefficients. Our work demonstrates that quadratic higher-curvature corrections induce non-zero but scale-independent tidal responses, offering a robust EFT framework to test deviations from GR in gravitational wave observations.

    ↳ hep-thastro-ph.HEgr-qchep-phJHEP(2025)·17 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.