Mon·Sep 8, 2025Monday·September 8, 2025

1. 01*

   Hyperon-Production Studies in $p+p\to \Lambda +K_S^0+p+{\pi }^{+}$ with HADES

   Snehankit Pattnaik🇩🇪 · Johan Messchendorp🇩🇪 · James Ritman🇩🇪

   The production mechanism of hyperons in the proton-proton collisions is explored using exclusive process with the data sample collected by HADES. The clear sign for three intermediate resonances is observed using simulated samples. It opens possibility for further detailed research.

   nucl-exhep-ex1 citation
2. 02*

   Measurement of the azimuthal anisotropy of charged particles in $\sqrt{s_{\mathrm{NN}}}=5.36$ TeV ${}^{16}$O${+}^{16}$O and ${}^{20}$Ne${+}^{20}$Ne collisions with the ATLAS detector

   ATLAS Collaboration

   This paper presents the first measurements of the azimuthal anisotropy coefficients $v_n$, which quantify the $n^{\mathrm{th}}$-order Fourier modulation of charged-particle azimuthal distributions, for $n=2$-4 in $\sqrt{s_{\mathrm{NN}}}=5.36$ TeV ${}^{16}\mathrm{O}+{}^{16}\mathrm{O}$ and ${}^{20}\mathrm{Ne}+{}^{20}\mathrm{Ne}$ collisions recorded with the ATLAS detector at the Large Hadron Collider in 2025. The $v_n$ coefficients are measured as a function of transverse momentum ($p_{\mathrm{T}}$), collision centrality, and event multiplicity. They are extracted using two complementary methods: two-particle correlations with a template-fit subtraction of short-range non-flow contributions, and four-particle subevent cumulants, which intrinsically suppress non-flow effects and provide sensitivity to flow fluctuations. The results show a clear hierarchy $v_2>v_3>v_4$ and a non-monotonic dependence on $p_{\mathrm{T}}$, reaching a maximum around 2 GeV, consistent with trends observed in heavy-ion collisions. Detailed comparisons between the two collision systems reveal an enhanced $v_2$ in central ${}^{20}\mathrm{Ne}+{}^{20}\mathrm{Ne}$ collisions, consistent with theory expectations based on the predicted prolate deformation of neon nuclei, in contrast to the slightly tetrahedral structure predicted for oxygen. The four-particle cumulant results highlight strong event-by-event fluctuations and provide the greatest sensitivity to nuclear shape effects. These measurements can place new constraints on the initial geometry and the hydrodynamic response in light-ion collisions, offering valuable input for models of nuclear structure.

   nucl-exhep-exPRC(2026)·62 citations
3. 03*

   rho-Meson Nucleon Scattering Length from CLAS Threshold Photoproduction Measurements

   Igor I. Strakovsky (GWU)🇺🇸 · Evgeny L. Isupov (MGU)🇷🇺 · Victor Mokeev (Jlab)🇺🇸 · Axel Schmidt (GWU)🇺🇸

   Extending our study of the vector meson-nucleon scattering lengths (summary is given in Ref.~\cite{Strakovsky:2021vyk}), we are focusing on the $\rho$-meson case using recent CLAS threshold data for the reaction $\gamma p\to \rho p$ within the meson-baryon reaction model~\cite{CLAS:2018drk}. The total ${\sigma }_t(\gamma p\to \rho p)$ and ${\sigma }_t(\gamma p\to \omega p)$ cross sections are close below the momentum of the vector meson in CM $q=0.2GeV/c$. Then the $\rho p$ photoproduction cross section grows rapidly. Our result for $\rho N$ scattering length is a factor of 4 smaller than the size of the hadron and the phenomenological determination of the $\omega$ nucleon scattering length using threshold photoproduction cross sections. The observed difference between $\rho N$ and $\omega N$ scattering lengths is of interest for further understanding within the hadron structure theory.

   ↳ nucl-thhep-exhep-phnucl-exPRD(2025)·5 citations
4. 04*

   Tensor-polarized twist-3 parton distribution functions $f_{LT}(x)$ for the spin-1 deuteron by using twist-2 relations

   S. Kumano🇨🇳 · Kenshi Kuroki🇨🇳

   Tensor-polarized twist-3 parton distribution functions (PDFs) $f_{LT}(x)$ are calculated for the spin-1 deuteron by using twist-2 relations, which are similar to the Wandzura-Wilczek relation and the Burkhardt-Cottingham sum rule in the spin-1/2 nucleon, together with tensor-polarized twist-2 PDFs $f_{1LL}(x)$. The PDFs are shown for $f_{LT}(x)$ at $Q^2=2.5$ GeV${}^2$, where the tensor-polarized PDFs $f_{1LL}(x)$ are provided. The $x$-dependence of $f_{LT}(x)$ is similar to $f_{1LL}(x)$, and the magnitude of $f_{LT}(x)$ is roughly of the order of $f_{1LL}(x)$. In experiments at the Thomas Jefferson National Accelerator Facility (JLab), higher-twist effects could be sizable because $Q^2$ values are not very large in comparison with the hadronic scale of 1 GeV${}^2$. Therefore, the JLab experiments could provide a good opportunity to investigate the twist-3 distributions $f_{LT}(x)$ in addition to the twist-2 ones $f_{1LL}(x)$. Furthermore, these tensor-polarized PDFs could be investigated at future Electron-Ion Colliders (EICs) and hadron accelerator facilities such as the Fermi National Accelerator Laboratory (Fermilab), the Nuclotron-based Ion Collider fAcility (NICA), and the Large Hadron Collider (LHC).

   ↳ hep-phhep-exhep-latnucl-ex+1PLB(2026)·6 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.