Critical mass in nonzero temperature QCD with staggered fermions

TL;DR

This paper studies the chiral phase transition in finite-temperature QCD with staggered fermions by analyzing the zeros of the partition function, revealing a weakly volume-dependent critical mass that decreases with temperature.

Contribution

It provides new insights into the finite-temperature chiral transition in QCD using partition function zeros, highlighting volume independence and temperature effects.

Findings

Evidence for a chiral transition at non-zero quark mass

Critical mass decreases with decreasing temperature

Transition is superimposed on smooth condensate behavior

Abstract

The behaviour of the chiral condensate in QCD is investigated by means of a study of the distribution of the zeros of the partition function in the complex quark mass plane. Simulations are performed at fixed temperature on three different spatial volumes at $\beta=5.04$ and at $\beta=4.9$ and $\beta=5.2$ on a $4^4$ lattice. Evidence is found for a chirally related transition at non-zero quark mass in the intermediate coupling region for $\beta < 5.2 $ but superimposed upon a smooth behaviour for the condensate. The critical mass at which this transition is found is only weakly dependent on the spatial volume and decreas with decreasing temperature.