Approaching the Continuum Limit of the Deconfinement Critical Point for $N_\text{f}=2$ Staggered Fermions

TL;DR

This study investigates the critical quark mass at which the deconfinement phase transition in two-flavor staggered fermion QCD changes from first-order to crossover, by performing lattice simulations at different lattice spacings.

Contribution

It provides new estimates of the $Z(2)$-critical quark mass for $N_f=2$ staggered fermions on finer lattices, advancing understanding of the continuum limit of the deconfinement critical point.

Findings

Critical mass results for $N_\tau=8$ and preliminary for $N_\tau=10$.

Finite size scaling analysis of the Polyakov loop kurtosis.

Extrapolation towards the continuum limit of the critical point.

Abstract

Quenched QCD at zero baryonic chemical potential undergoes a first-order deconfinement phase transition at a critical temperature $T_c$, which is related to the spontaneous breaking of the global center symmetry. The center symmetry is broken explicitly by including dynamical quarks, which weaken the first-order phase transition for decreasing quark masses. At a certain critical quark mass, which corresponds to the $Z(2)$-critical point, the first-order phase transition turns into a smooth crossover. We investigate the $Z(2)$-critical quark mass for $N_\text{f}=2$ staggered fermions on $N_\tau=8, 10$ lattices, where larger $N_\tau$ correspond to finer lattices. Monte-Carlo simulations are performed for several quark mass values and aspect ratios in order to extrapolate to the thermodynamic limit. We present final results for $N_\tau=8$ and preliminary results for $N_\tau=10$ for the critical mass, which are obtained from fitting to a kurtosis finite size scaling formula of the absolute value of the Polyakov loop.