Excluded-volume effects for a hadron gas in Yang-Mills theory

TL;DR

This paper investigates how excluded-volume effects influence the equation of state in pure Yang-Mills theories, revealing that glueball volume inversely correlates with mass improves model fits to lattice data.

Contribution

It introduces a detailed analysis of excluded-volume effects in Yang-Mills theories and proposes a volume-mass inverse proportionality for glueball states, enhancing the statistical model's accuracy.

Findings

Best fits occur with glueball volume inversely proportional to mass

The model aligns well with lattice results for SU(2) and SU(3)

Implications discussed for QCD thermodynamics

Abstract

When the multiplicities of particles produced in heavy-ion collisions are fitted to the hadron-resonance-gas model, excluded-volume effects play a significant role. In this work, we study the impact of such effects on the equation of state of pure Yang-Mills theory at low temperatures, comparing the predictions of the statistical model with lattice results. In particular, we present a detailed analysis of the SU(2) and SU(3) Yang-Mills theories: we find that, for both of them, the best fits to the equilibrium thermodynamic quantities are obtained when one assumes that the volume of different glueball states is inversely proportional to their mass. The implications of these findings for QCD are discussed.