Deconfinement and chiral transition with the highly improved staggered quark (HISQ) action

TL;DR

This study investigates the finite temperature chiral and deconfinement transitions in 2+1 flavor QCD using the HISQ action, analyzing various observables and comparing with other fermion formulations.

Contribution

It provides new insights into the QCD transition using the HISQ action on lattices with N_tau=6 and 8, including physical quark masses and multiple observables.

Findings

Consistent signals of chiral and deconfinement transitions observed.

Comparison shows HISQ results align well with other improved staggered formulations.

Finite temperature observables exhibit expected behavior near transition temperature.

Abstract

We report on investigations of the chiral and deconfinement aspects of the finite temperature transition in 2+1 flavor QCD using the Highly Improved Staggered Quark (HISQ) action on lattices with temporal extent $N_\tau=6$ and $N_\tau=8$. We have performed the calculations for physical values of the strange quark mass $m_s$ and the light quark masses $m_l=0.2m_s$ and $0.05m_s$. Several finite temperature observables, including the renormalized Polyakov loop, the renormalized chiral condensate and the chiral susceptibility have been calculated. We also study the fluctuations and correlations of different conserved charges as well as the trace anomaly at finite temperature. We compare our findings with previous calculations that use different improved staggered fermion formulations: asqtad, p4 and stout.