Free energies of heavy quarks in full-QCD lattice simulations with Wilson-type quark action

TL;DR

This study investigates the free energy of heavy quarks in full-QCD lattice simulations with Wilson-type quarks, revealing how the interaction behaves at different distances and comparing screening effects with perturbation theory.

Contribution

It provides the first detailed lattice QCD analysis of heavy-quark free energies with Wilson-type quarks across various temperatures and distances, confirming expected short-range and long-range behaviors.

Findings

Short-distance free energies match zero-temperature potentials.

Long-distance free energies indicate screening effects.

Debye mass agrees with thermal perturbation theory.

Abstract

The free energy between a static quark and an antiquark is studied by using the color-singlet Polyakov-line correlation at finite temperature in lattice QCD with 2+1 flavors of improved Wilson quarks. From the simulations on $32^3 \times 12$, 10, 8, 6, 4 lattices in the high temperature phase, based on the fixed scale approach, we find that, the heavy-quark free energies at short distance converge to the heavy-quark potential evaluated from the Wilson loop at zero temperature, in accordance with the expected insensitivity of short distance physics to the temperature. At long distance, the heavy-quark free energies approach to twice the single-quark free energies, implying that the interaction between heavy quarks is screened. The Debye screening mass obtained from the long range behavior of the free energy is compared with the results of thermal perturbation theory.