Temperature and chemical potential dependence of the gluon condensate: a holographic study

TL;DR

This paper investigates how the gluon condensate varies with temperature and chemical potential using a holographic QCD model, revealing temperature dependence and independence from chemical potential at high temperatures.

Contribution

It introduces a holographic approach to analyze the gluon condensate's behavior at finite temperature and chemical potential, including separate evaluations of electric and magnetic components.

Findings

Gluon condensate is temperature-dependent at low T.

At high T, the condensate becomes independent of chemical potential.

The electric and magnetic components of the condensate are separately characterized.

Abstract

The lowest dimensional gluon condensate $G_2$ is analyzed at finite temperature and chemical potential using a holographic model of QCD with conformal invariance broken by a background dilaton. Starting from the free energy of the model, the thermodynamical quantities needed to determine the $T$ and $\mu$ dependence of the gluon condensate are evaluated. At high temperature the gluon condensate is independent of chemical potential. Moreover, at $\mu=0$ and in the string frame, the temporal and spatial Wilson loops at low temperature are computed; they are related to the (chromo) electric and magnetic components of $G_2$, respectively. The $T$-dependence of the two components is separately determined.