Fri·Mar 14, 2025Friday·March 14, 2025

1. 01*

   Signs of Non-Monotonic Finite-Volume Corrections to $g_A$

   Zack B. Hall🇺🇸 · Dimitra A. Pefkou🇺🇸 · Aaron S. Meyer🇺🇸 · Thomas R. Richardson🇺🇸 · Raúl A. Briceño🇺🇸 · M. A. Clark🇺🇸 · Martin Hoferichter🇨🇭 · Emanuele Mereghetti🇺🇸 · Henry Monge-Camacho🇺🇸 · Colin Morningstar🇺🇸 · Amy Nicholson🇺🇸 · Pavlos Vranas🇺🇸 · André Walker-Loud🇺🇸

   We study finite-volume (FV) corrections to determinations of $g_A$ via lattice quantum chromodynamics (QCD) using analytic results and numerical analysis. We observe that $SU(2)$ Heavy Baryon Chiral Perturbation Theory does not provide an unambiguous prediction for the sign of the FV correction, which is not surprising when one also considers large-$N_c$ constraints on the axial couplings. We further show that non-monotonic FV corrections are naturally allowed when one considers either including explicit $\Delta$-resonance degrees of freedom or one works to higher orders in the chiral expansion. We investigate the potential impact of these FV corrections with a precision study of $g_A$ using models of FV corrections that are monotonic and non-monotonic. Using lattice QCD data that is approximately at the 1% level of precision, we do not see significant evidence of non-monotonic corrections. Looking forward to the next phase of lattice QCD calculations, we estimate that calculations that are between the 0.1%-1%-level of precision may be sensitive to these FV artifacts. Finally, we present an update of the CalLat prediction of $g_A$ in the isospin limit with sub-percent precision, $g_A^{\mathrm{QCD}}=1.2674(96)$.

   ↳ hep-lathep-phnucl-exnucl-thPRC(2026)·21 citations
2. 02*

   Light Pentaquark Searches with Hadron Beams

   Jung Keun Ahn🇰🇷

   This review deals with measurements and future experiments of light pentaquark searches using hadron beams.

   ↳ hep-phhep-exnucl-exActa Phys.Polon.B(2025)·0 citations
3. 03*

   Bayesian analysis of a (3+1)D hybrid approach with initial conditions from hadronic transport

   Niklas Götz🇩🇪 · Iurii Karpenko🇨🇿 · Hannah Elfner🇩🇪

   This study aims to apply statistical learning, specifically Bayesian inference, to the (3+1)D SMASH-vHLLE-hybrid model using initial conditions generated by the SMASH transport code itself, with the objective of constraining model parameters and gaining deeper insight on the temperature and baryochemical potential dependence of both the shear and the bulk viscosity. This study is performed in the hybrid approach SMASH-vHLLE, composed of the hadronic transport approach SMASH and the (3+1)D viscous hydrodynamic code vHLLE. A Bayesian framework is employed, utilizing Markov Chain Monte Carlo (MCMC) sampling to explore the parameter space. The analysis compares model predictions against experimental observables, including particle yields, momentum and flow coefficients both at midrapidity as well as in forward and backward direction. We find that the SMASH-vHLLE-hybrid framework, using hadronic initial conditions for Au+Au collisions at different beam energies, can reproduce a variety of experimental observables at midrapidity and forward/backward rapidities. Notably, the preferred posterior distribution suggests a near-vanishing specific shear viscosity in the high-temperature QGP phase, combined with moderate-to-large bulk viscosity around the phase transition region, although the constraints on baryochemical potential dependence are weak. Our findings reveal that a hadronic initial condition constrains the evolution more strictly at intermediate energies, making parameters such as the hydrodynamic onset time highly sensitive. Intriguingly, the extracted shear viscosity differs substantially from previous Bayesian analyses, motivating further systematic studies with higher-statistics data sets and refined modeling assumptions.

   ↳ nucl-thhep-phnucl-exPRC(2025)·21 citations
4. 04*

   Explanation of the observed violation of isospin symmetry in relativistic nucleus-nucleus reactions

   Tom Reichert🇩🇪 · Jan Steinheimer🇩🇪 · Marcus Bleicher🇩🇪

   The violation of isospin symmetry in nucleus-nucleus reactions, as shown in the ratio $R_K=(K^{+}+K^{-})/(K^0+{\bar{K}}^0)$ presented by NA61/SHINE, can be understood by introducing results from color-string fragmentation in $e^{+}{e}^{-}$ to nuclear reactions. This novel input allows for a consistent description of the $e^{+}{e}^{-}$ data, proton+proton data and finally nucleus-nucleus data at all investigated energies. We conclude that the observed isospin violation in nucleus-nucleus reactions is explained by asymmetric production of up- and down-quarks in the elementary color field fragmentation process.

   ↳ nucl-thhep-phnucl-exPLB(2026)·7 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.