Quark deconfinement and meson properties at finite temperature

TL;DR

This paper uses a simplified QCD model to study how meson properties and quark confinement change with temperature, revealing slow mass variation until near the deconfinement point and comparing results with lattice simulations.

Contribution

It introduces a confining separable interaction model within Dyson-Schwinger equations to analyze meson behavior at finite temperature, highlighting the transition near deconfinement.

Findings

Meson masses remain nearly constant until close to T_c

Masses increase significantly above T_c, interpreted as screening masses

Model results agree with lattice gauge theory simulations

Abstract

A simple confining separable interaction Ansatz for the rainbow-ladder truncated QCD Dyson-Schwinger equations is used to study quark deconfinement and meson states at finite temperature. The model is fixed at T=0 to implement quark confinement while preserving the Goldstone mechanism for the $\pi$. Within the Matsubara formalism, a very slow temperature dependence is found for the $\pi$ and $\rho$ meson masses $M_H(T)$ until near the deconfinement temperature $T_c=143$ MeV. Related to rapid decrease of the dynamically-generated quark mass function for $T>T_c$, this model produces $\pi$ and $\rho$ masses that rise significantly and are better interpreted as spatial screening masses. The $T$-dependent screening mass defect $\Delta M_H = 2\pi T-M_H(T)$ is compared to results of lattice gauge theory simulations and also to those of an infrared dominant analytic model.