Color screening in 2+1 flavor QCD and at weak coupling

Abstract

We study spatial correlation functions of static quark-antiquark pairs in QCD with 2+1 flavors in order to better understand color screening at high temperatures. We performed lattice simulations in a wide temperature window $115\,{\rm MeV}\lesssim T\lesssim 5.8\,{\rm GeV}$ using the using the highly improved staggered quark (HISQ) action, the tree-level improved Symanzik gauge action and several lattice spacings to control discretization effects. By comparing our lattice results to analytic calculations at weak coupling as well as to the zero temperature result on the static energy we demonstrate that color screening sets in at distances $rT \simeq 0.25$. We also conclude that in the distance regime $0.25<r T< 0.6$ the weak-coupling approach provides an adequate description of color screening.