Thermodynamics from the quark condensate

TL;DR

This paper introduces a truncation-independent method to compute thermodynamic quantities in quantum chromodynamics using Dyson-Schwinger equations, demonstrated through models and actual QCD solutions.

Contribution

It develops a novel approach for calculating thermodynamics in continuum QCD frameworks that avoids dependence on truncation schemes.

Findings

Successfully applied to a NJL model in mean-field approximation.

Extended to Dyson-Schwinger equations for (2+1)-flavor QCD.

Provided thermodynamic quantities across the QCD phase diagram.

Abstract

We present a method to compute thermodynamic quantities within functional continuum frameworks that is independent of the employed truncation. As a proof of principle, we first apply it to a Nambu-Jona-Lasinio model in mean-field approximation. Then, we use the method with solutions obtained from a coupled set of truncated Dyson-Schwinger equations for the quark and gluon propagators of (2+1)-flavor quantum chromodynamics in Landau gauge to obtain the pressure, entropy density, energy density, and interaction measure across the phase diagram of strong-interaction matter. We also discuss the limitation of the proposed method.