Influence of excluded volume corrections on hadronic yield in high-energy nuclear collisions

Abstract

This article presents a comprehensive study of various particle ratios involving strange and non-strange hadrons across a wide range of center-of-mass energies from the lowest energies at the Relativistic Heavy Ion Collider (RHIC) to the highest at the Large Hadron Collider (LHC). We utilize the excluded-volume hadron resonance gas (EV-HRG) model to calculate these ratios, assigning a hard-core size to each baryon and anti-baryon to account for repulsive interactions. To explore potential differences in the production mechanisms of strange versus non-strange hadrons, we incorporate a strangeness suppression factor (\(\gamma _s\)) into our formulation. Additionally, we compare our results with those obtained from other theoretical approaches, including the van der Waals (vdW) model, transport models such as the A Multi-Phase Transport (AMPT) model and the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) model, as well as from effective theory frameworks like the Nambu–Jona–Lasinio (NJL) model. Our analysis shows that a baryon and anti-baryon hard-core radius of 0.59 fm provides a good fit to the experimental data. Overall, this study highlights the strengths and predictive accuracy of various statistical thermal, transport, and effective theory models, with the EV-HRG model demonstrating particularly strong agreement with experimental observations.