Quark spectral properties above Tc from Dyson-Schwinger equations

TL;DR

This paper investigates the properties of quark spectral functions at finite temperature using Dyson-Schwinger equations, revealing differences across the deconfinement transition and comparing with lattice QCD results.

Contribution

It provides a detailed analysis of quark spectral functions above and below Tc using Dyson-Schwinger equations and applies the Maximum Entropy Method for spectral reconstruction.

Findings

Agreement with lattice QCD results in Euclidean space

Different analytical properties of the quark propagator across Tc

Insights into quark mass and momentum dependence at high temperature

Abstract

We report on an analysis of the quark spectral representation at finite temperatures based on the quark propagator determined from its Dyson-Schwinger equation in Landau gauge. In Euclidean space we achieve nice agreement with recent results from quenched lattice QCD. We find different analytical properties of the quark propagator below and above the deconfinement transition. Using a variety of ansaetze for the spectral function we then analyze the possible quasiparticle spectrum, in particular its quark mass and momentum dependence in the high temperature phase. This analysis is completed by an application of the Maximum Entropy Method, in principle allowing for any positive semi-definite spectral function. Our results motivate a more direct determination of the spectral function in the framework of Dyson-Schwinger equations.