Dae Ik Kim, Chang-Hwan Lee, Kyungil Kim, Youngman Kim, Sangyong Jeon, Kazuo Tsushima

Physical Review C

20/02/2026

Abstract

The quark-meson coupling (QMC) model incorporates quark degrees of freedom into the relativistic mean-field (RMF) framework, distinguishing it from traditional quantum hadrodynamics (QHD), which treats nucleons as pointlike particles. In this work, we implement the QMC model within the DaeJeon Boltzmann-Uehling-Uhlenbeck (DJBUU) transport code to investigate its applicability to intermediate-energy heavy-ion collisions. We simulate 197Au+197Au collisions at a beam energy of 400⁢𝐴 MeV using both QHD and QMC and find that the two approaches yield comparable results for bulk observables such as transverse and directed flow, with good agreement with experimental data. To further assess the model performance, we study pion production in neutron-rich (132Sn+124Sn) and less neutron-rich (108Sn+112Sn) systems at 270⁢𝐴 MeV. In contrast to the QHD case, reproducing the observed pion yields and charge ratios within the QMC framework requires a slightly reduced density-dependent suppression in the in-medium Δ production cross section. These results demonstrate that the QMC model can be effectively integrated into transport simulations.

10.1103/fqkq-hs7h