Rapidity density distributions of identified particles and light nuclei in Au+Au collisions at $\sqrt{s_{NN}}$ = 3 GeV using Boltzmann-Gibbs thermodynamics and its implication

摘要: We investigate the rapidity density distributions of identified particles and light nuclei produced in Au+Au collisions at $\sqrt{s_{NN}}$ = 3 GeV, measured by the STAR experiment at the BNL Relativistic Heavy Ion Collider (RHIC), using a fireball model with Boltzmann-Gibbs thermodynamics. The fireball model provides a satisfactory description of the experimental data for identified mesons and baryons across all centrality classes. This overall consistency demonstrates that the fireball model provides a useful phenomenological framework for describing the measured rapidity distributions. However, the description requires species-dependent values of the effective temperature and fireball-shape parameters. While the model reasonably reproduces the rapidity density distributions of deuterons ($d$) produced in central and semi-central collisions, it fails to reproduce their rapidity density distributions in peripheral collisions, as well as those for heavier light nuclei with $A\ge 3$. These results imply that light nuclei produced in high-energy heavy-ion collisions originate from a different particle production mechanism than the identified hadrons.