Thermodynamics and fluctuations of conserved charges in Hadron Resonance Gas model in finite volume

TL;DR

This paper investigates how finite volume effects influence thermodynamic properties and charge fluctuations in the Hadron Resonance Gas model, finding minimal impact except for electric charge fluctuations which can inform about the system size.

Contribution

It introduces finite volume considerations into the Hadron Resonance Gas model and identifies electric charge fluctuations as a key observable for system size estimation.

Findings

Finite size effects are negligible when scaled by volume.

Electric charge fluctuations are sensitive to system size.

Fluctuations can be used to estimate the fireball volume in experiments.

Abstract

The thermodynamics of hot and dense matter created in heavy-ion collision experiments are usually studied as a system of infinite volume. Here we report on possible effects for considering a finite system size for such matter in the framework of the Hadron Resonance Gas model. The bulk thermodynamic variables as well as the fluctuations of conserved charges are considered. We find that the finite size effects are insignificant once the observables are scaled with the respective volumes. The only substantial effect is found in the fluctuations of electric charge which may therefore be used to extract information about the volume of fireball created in heavy-ion collision experiments.