Hadron resonance gas model with repulsive mean-field interactions: specific heat, isothermal compressibility and speed of sound

TL;DR

This paper studies how repulsive mean-field interactions among hadrons influence thermodynamic properties like specific heat, compressibility, and speed of sound in hot dense matter, comparing results with lattice QCD data and discussing implications for heavy-ion collisions.

Contribution

It introduces a mean-field approach with different interactions for mesons and baryons to analyze thermodynamic properties of hadronic matter, aligning findings with lattice QCD results.

Findings

Repulsive interactions significantly affect specific heat and speed of sound.

Effect on isothermal compressibility is mild.

Results have implications for interpreting heavy-ion collision experiments.

Abstract

We investigate the effect of repulsive interaction between hadrons on the specific heat ($C_V$), isothermal compressibility ($\kappa_{T}$) and the speed of sound ($C_s^2$) of hot and dense hadronic matter. The repulsive interactions are included through a mean-field approach where the single particle energy picks correction term due to mean field interactions between hadrons. This correction term is proportional to the number density of hadrons. We assume different mean-field interactions for mesons and baryons. We also confront $C_V$ and $C_s^2$ with existing lattice QCD simulation results. We find that the repulsive interactions have very strong effect on $C_V$ and $C_s^2$ while its effect on $\kappa_T$ is very mild. We finally discuss the implications of our results in the context of heavy-ion collision experiments.