Static $\bar{Q}Q$ pair free energy and screening masses from correlators of Polyakov loops: continuum extrapolated lattice results at the QCD physical point

TL;DR

This study computes the free energy of static quark-antiquark pairs in 2+1 flavor QCD at finite temperature using lattice simulations, extracting screening masses and continuum extrapolated results with improved actions.

Contribution

It provides continuum-limit results for Polyakov loop correlators and distinguishes electric and magnetic screening masses in full QCD at physical quark masses.

Findings

Continuum extrapolated free energies from Polyakov loop correlators.

Extraction of electric and magnetic screening masses.

Results at multiple lattice spacings and physical quark masses.

Abstract

We study the correlators of Polyakov loops, and the corresponding gauge invariant free energy of a static quark-antiquark pair in 2+1 flavor QCD at finite temperature. Our simulations were carried out on $N_t$ = 6, 8, 10, 12, 16 lattices using Symanzik improved gauge action and a stout improved staggered action with physical quark masses. The free energies calculated from the Polyakov loop correlators are extrapolated to the continuum limit. For the free energies we use a two step renormalization procedure that only uses data at finite temperature. We also measure correlators with definite Euclidean time reversal and charge conjugation symmetry to extract two different screening masses, one in the magnetic, and one in the electric sector, to distinguish two different correlation lengths in the full Polyakov loop correlator.