Screening at finite temperature and density

TL;DR

This paper investigates how static quark-antiquark interactions are affected by temperature and density in lattice QCD, revealing medium effects and screening phenomena relevant for understanding quark matter under extreme conditions.

Contribution

It provides new lattice QCD results on heavy quark free energies, entropy, and internal energy at finite temperature and density with realistic quark masses, including density dependence of screening masses.

Findings

Identification of medium effects leading to screening in a thermal medium.

Quantitative analysis of entropy and internal energy contributions at finite temperature.

Results on the density dependence of screening masses using Taylor expansion.

Abstract

We present lattice QCD results on heavy quark free energies, extract from its temperature dependence entropy and internal energy contributions, and discuss the onset of medium effects that lead to screening of static quark-antiquark sources in a thermal medium. Most results are obtained in (2+1)-flavour QCD on a line of constant physics with almost realistic quark masses and compared to previous results from 2-flavor QCD as well as pure gauge theory. Furthermore, we discuss results on the density dependence of screening masses that have been obtained using a leading order Taylor expansion in the baryon chemical potential.