Hadron Resonance Gas with Repulsive Interactions and Fluctuations of Conserved Charges

TL;DR

This paper investigates how repulsive interactions among baryons influence fluctuations and correlations in a hadron gas, comparing theoretical models with lattice QCD results to understand signals of deconfinement.

Contribution

It introduces a combined approach using relativistic virial expansion and mean field methods to incorporate repulsive interactions in the hadron resonance gas model, and compares results with lattice QCD data.

Findings

Repulsive interactions can explain certain fluctuation differences at moderate temperatures.

The model reproduces lattice QCD results for baryon number fluctuations.

Differences in higher-order fluctuations serve as potential probes of deconfinement.

Abstract

We discuss the role of repulsive baryon-baryon interactions in a hadron gas using relativistic virial expansion and repulsive mean field approaches. The fluctuations of the baryon number as well as strangeness-baryon correlations are calculated in the hadron resonance gas with repulsive interactions and compared with the recent lattice QCD results. In particular, we calculate the difference between the second and fourth order fluctuations and correlations of baryon number and strangeness, that have been proposed as probes of deconfinement. We show that for not too high temperatures these differences could be understood in terms of repulsive interactions.