Can we decide whether QCD is confining or not at high temperature?

TL;DR

This paper investigates whether QCD is confining or deconfining at high temperatures by analyzing symmetry properties and correlation functions, beyond traditional order parameters like the Polyakov loop.

Contribution

It proposes using SU(2)_CS and SU(4) symmetries of confinement to distinguish phases in high-temperature QCD where standard order parameters are insufficient.

Findings

Correlation functions reveal symmetry patterns indicative of confinement or deconfinement.

SU(2)_CS and SU(4) symmetries can serve as alternative indicators of the QCD phase.

The approach offers a new perspective on the QCD phase diagram at high temperatures.

Abstract

At high temperature measurements of the Polyakov loop suggest a deconfinement transition to the (strongly interacting) quark-gluon plasma. At the same time at the infinitely large temperature the four-dimensional QCD is reduced to the three-dimensional QCD that is confining. The Polyakov loop and related Z_3 symmetry are strict order parameters only for infinitely heavy quarks. In such a situation the SU(2)_CS and SU(4) symmetries of confinement in the light quark sector could be helpful to distinguish between the confining and deconfining phase in a regime where SU(2)_L \times SU(2)_R and U(1)_A symmetries are manifest. In order to reveal a presence or absence of these symmetries one needs to measure and compare correlation functions related by these symmetry transformations.