Entropy in the quark-hadron transition

TL;DR

This paper investigates how entropy reflects the change in effective degrees of freedom during the quark-hadron transition using the PNJL model, highlighting the role of mesonic correlations and phase transition characteristics.

Contribution

It introduces a detailed analysis of entropy behavior across the quark-hadron transition within the PNJL model, emphasizing the impact of mesonic correlations.

Findings

Entropy increases with temperature, indicating a shift from mesonic to quark degrees of freedom.

The model predicts a second order deconfinement transition in the chiral limit.

Mesonic correlations significantly influence the effective degrees of freedom.

Abstract

We study, in the PNJL model, how the entropy of interacting quarks reflects the change in the effective degrees of freedom as the temperature increases through the quark-hadron phase transition. With inclusion of mesonic correlations, the effective degrees of freedom change from those of pi and sigma mesons at low temperatures to those of free quarks at high temperatures, with a resultant second order phase deconfinement transition in the chiral limit.