The spatial string tension and its effects on screening correlators in a thermal QCD plasma

TL;DR

This study investigates the spatial string tension in thermal QCD, revealing non-perturbative magnetic gluon interactions at high temperatures and supporting the applicability of dimensionally reduced theories for describing soft quark and gluon quasi-particles across a wide temperature range.

Contribution

It provides the first evidence of non-perturbative effects in the pseudo-potential influencing mesonic screening masses up to 164 GeV.

Findings

Non-perturbative magnetic gluon interactions persist above 1 GeV.

Dimensionally reduced effective theories describe soft quasi-particles at T > 5T_{pc}.

Non-perturbative pseudo-potential impacts mesonic screening masses across a broad temperature range.

Abstract

We calculate the spatial Wilson line correlator for 2+1 flavor QCD using highly improved staggered quark discretization for fermions and in quenched QCD for a wide range of temperatures, from the chiral crossover temperature $\mathrm{T_{pc}\simeq 156}$ MeV or the deconfinement temperature $\simeq 300$ MeV respectively, up to $2$ GeV. Extracting the spatial string tension for different lattice cut-offs and by performing a continuum extrapolation of this observable, we show that the soft (magnetic) gluons interact non-perturbatively even at temperatures $\gtrsim 1$ GeV. We provide incriminating evidences to demonstrate that dimensionally reduced effective theories can describe these soft quark and gluon quasi-particles for both quenched and $2+1$ flavor QCD, at temperatures $\mathrm{T\gtrsim 5T_{pc}}$. We also show for the first time the imprints of the non-perturbative pseudo-potential in the properties of mesonic screening masses for temperatures ranging from $0.8$-$164$ GeV in the quark-gluon plasma.