Fri·Aug 1, 2025Friday·August 1, 2025

1. 01*

   Studying Two-Photon Exchange in Deep Inelastic Scattering with the HERA Data

   Henry T. Klest🇺🇸

   Two-photon exchange (TPE) is one of the leading explanations for discrepancies in measurements of the proton electromagnetic form factors. It has been proposed that TPE could impact not only elastic scattering, but also the cross sections for both inclusive deep inelastic scattering (DIS) and semi-inclusive DIS, thereby affecting the interpretation of DIS structure functions in terms of parton distributions. It is expected that higher-order QED effects such as TPE should manifest as a deviation from unity in the ratio of \epp and \emp DIS cross sections. We use the existing inclusive $e^{\pm }p$ DIS data from HERA and SLAC to constrain higher-order QED effects on inclusive DIS.

   ↳ hep-phhep-exnucl-exPRD(2026)·3 citations
2. 02*

   Mapped $spdf$ interacting boson model for quadrupole-octupole collective states in nuclei

   K. Nomura🇯🇵

   Dipole bosons are introduced in the interacting boson model (IBM) by means of the self-consistent mean-field method. The constrained mean-field calculations employing a given nuclear energy density functional yield the potential energy surfaces in terms of the axially-symmetric quadrupole-octupole, dipole-quadrupole, and dipole-octupole deformations. By mapping these energy surfaces onto the expectation values of the IBM Hamiltonian in the coherent state of the interacting $s$, $p$, $d$, and $f$ bosons, strength parameters of the $spdf$-IBM Hamiltonian are determined. In an illustrative application to octupole-deformed actinides ${}^{218-230}$Ra and ${}^{220-232}$Th, it is shown that effects of including $p$ bosons in the IBM mapping are to lower significantly negative-parity yrast levels, and to improve descriptions of observed energy-level systematic in nearly spherical and transitional nuclei, and of the behaviors of the reduced electric dipole transitions and intrinsic dipole moments with neutron number.

   ↳ nucl-thnucl-exPRC(2025)·2 citations
3. 03*

   Poincaré covariant quantum molecular dynamics: a covariant description of a system of interacting wave packets

   Yasushi Nara🇯🇵 · Asanosuke Jinno🇯🇵 · Koichi Murase🇯🇵

   We present a new formulation for the mean-field propagation part of the relativistic quantum molecular dynamics, simulating an $N$-body system of interacting Gaussian wave packets via Lorentz scalar and vector potentials. Covariant equations of motion are derived based on the principle of least action. These covariant equations of motion can be solved with a computational cost comparable to that of conventional noncovariant quantum molecular dynamics. Furthermore, the new equations of motion accurately estimate the density-dependent potential, as demonstrated through comparison of the forces with the numerical integration. We apply them to $N$-body systems interacting via the Skyrme-type potentials or the relativistic mean field to simulate heavy-ion collisions. Our results show that the derived equations of motion provide a robust approximation to the dynamics of the full numerical integrations.

   ↳ hep-phnucl-exnucl-th2 citations
4. 04*

   Probing Cosmic Ray Composition and Muon-philic Dark Matter via Muon Tomography

   Cheng-en Liu🇨🇳 · Rongfeng Zhang🇨🇳 · Zijian Wang🇨🇳 · Andrew Michael Levin🇨🇳 · Leyun Gao🇨🇳 · Jinning Li🇨🇳 · Minxiao Fan🇨🇳 · Youpeng Wu🇨🇳 · Zibo Qin🇨🇳 · Yong Ban🇨🇳 · Zaihong Yang🇨🇳 · Qite Li🇨🇳 · Chen Zhou🇨🇳 · Qiang Li🇨🇳

   This work presents a novel cosmic-ray scattering experiment employing a Resistive Plate Chambers (RPC) muon tomography system. By introducing the scattering angle between incident and outgoing cosmic-ray tracks as a key observable, this approach enables simultaneous studies of secondary cosmic-ray composition and searching for new physics. During a 63-day campaign, 1.18 million cosmic ray scattering events were recorded and analyzed. By performing combined template fits to the observed angular distribution, particle abundances are measured -- for example, resolving the electron component at $\sim 2\%$ precision. Furthermore, constraints are established on elastic muon dark matter (DM) scattering cross-sections for muon-philic dark matter. At the $95\%$ confidence level, the limit reaches 1.61 $\times$ $10^{-17}$ ${\mathrm{cm}}^2$ for 1 GeV slow DM, demonstrating sensitivity limit to light muon-coupled slow DM, in scenarios where a strongly interacting dark matter component is captured and thermalized within the Earth, leading to large surface densities.

   ↳ hep-exastro-ph.HEhep-phnucl-exPRL(2026)·3 citations
5. 05*

   Production of Jets at STAR

   Michal Svoboda🇨🇿

   Jets serve as an important tool to probe QCD both in the vacuum and in the hot and dense medium. The STAR experiment at RHIC plays a key role in studying QCD phenomena across different collision systems ($p$+$p$, $p$+A, A+A), offering access to a kinematic regime that complements that of the LHC. Building on recent jet and event activity studies at STAR, we present recent measurements on charged-particle jets at $\sqrt{s_{\mathrm{NN}}}=200$ GeV. In $p$+Au collisions, we explore event activity (EA) measured in the Au-going direction and its correlation with particle production at mid-rapidity. While soft particle production increases with EA, high-$p_{\mathrm{T}}$ jets are found to be inversely related to EA. Ratios of $p_{\mathrm{T}}$ imbalance and azimuthal dijet separation between high- and low-EA events show no significant differences, suggesting no strong evidence of jet quenching in high-EA $p$+Au collisions. In Au+Au collisions, we report semi-inclusive measurements of jets recoiling from $\gamma$ and ${\pi }^0$ triggers, using mixed-event techniques to subtract background and study jet suppression, intra-jet broadening, and acoplanarity. Additionally, we present inclusive charged-particle jet spectra corrected for background fluctuations, extending the kinematic reach of previous measurements. These results provide crucial insight into the modification of jets in the medium and contribute to a deeper understanding of QCD in heavy-ion collisions.

   ↳ hep-exnucl-ex0 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.