Thermodynamics of an exactly solvable confining quark model

TL;DR

This paper presents an exact calculation of the thermodynamics of a confining quark model inspired by nonperturbative QCD, revealing stable behavior and results consistent with lattice simulations across various temperatures and densities.

Contribution

It introduces an exactly solvable confining quark model with a nonperturbative quark mass function, providing insights into thermodynamics at finite temperature and density.

Findings

Thermodynamic quantities match lattice simulation trends.

Model exhibits stable behavior at all temperatures and chemical potentials.

Finite density results deviate from ideal gas predictions.

Abstract

The grand partition function of a model of confined quarks is exactly calculated at arbitrary temperatures and quark chemical potentials. The model is inspired by a softly BRST-broken version of QCD and possesses a quark mass function compatible with nonperturbative analyses of lattice simulations and Dyson-Schwinger equations. Even though the model is defined at tree level, we show that it produces a nontrivial and stable thermodynamic behaviour at any temperature or chemical potential. Results for the pressure, the entropy and the trace anomaly as a function of the temperature are qualitatively compatible with the effect of nonperturbative interactions as observed in lattice simulations. The finite density thermodynamics is also shown to contain nontrivial features, being far away from an ideal gas picture.