Description of bulk properties of charged pions, kaons, and (anti)protons in Au+Au collisions from the STAR experiment in the Beam Energy Scan program within the improved HIJING code: Role of initial-state interactions

Abstract

We have investigated the production yields of charged pions, kaons, and (anti)protons (restricted to midrapidity of $|y|l0.1$) in $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{{s}_{NN}}=7.7,\phantom{\rule{0.16em}{0ex}}11.5,\phantom{\rule{0.16em}{0ex}}19.6,\phantom{\rule{0.16em}{0ex}}27$, and 39 GeV, from the STAR experiment in the Beam Energy Scan (BES) program at the Relativistic Heavy Ion Collider (RHIC), within an improved heavy-ion jet interaction generator (ImHIJING) code plus a relativistic transport (ART) model. Improvements of the dynamical content of ImHIJING code include (i) sampling of initial momenta of nuclear ground state, (ii) a Regge cascade for initial-state interaction effects, and (iii) an advanced popcorn mechanism for baryon production. It is found that the implementation of initial-state interactions in the $\mathrm{ImHIJING}+\mathrm{ART}$ model is crucial for the description of collision centrality dependence of bulk hadron observables in peripheral and semicentral ($\ensuremath{\approx}10%$--$70%$) $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{{s}_{NN}}g11.5$ GeV.