QCD Sum Rules at High Temperature

TL;DR

This paper extends QCD sum rules to high-temperature regimes, revealing that QCD maintains color singlet excitations in vector channels above the critical temperature, contrary to expectations of simple screening.

Contribution

It introduces a generalized sum rule approach incorporating condensates to analyze nonperturbative QCD at high temperature, highlighting the persistence of color singlet states.

Findings

QCD exhibits color singlet excitations above T_c

Sum rules include power corrections from condensates

QCD at high temperature differs from simple quark-gluon plasma

Abstract

We generalize the sum rule approach to investigate the nonperturbative structure of QCD at high temperature. Salient features of the QCD phase above $T_c$ are discussed, and included in the form of power corrections or condensate insertions, in an operator product expansion of gauge invariant correlators. It is shown that for a plausible choice of condensates, QCD at high temperature exhibits color singlet excitations in the vector channels, as opposed to merely screened quarks and gluons.