Width of the QCD transition in a Polyakov-loop DSE model

TL;DR

This paper investigates the width of the QCD transition using a Polyakov-loop Dyson-Schwinger equation model, analyzing how coupling and potential rescaling affect the transition's nature and temperature range.

Contribution

It introduces a detailed analysis of the QCD transition width and the effects of Polyakov-loop coupling and potential rescaling within a nonlocal Dyson-Schwinger framework.

Findings

Coupling the quark and gluon sectors synchronizes the pseudocritical temperatures.

Rescaling T_0 affects the transition width, especially for the logarithmic potential.

Transition character changes from crossover to first order for T_0 < 210 MeV with the logarithmic potential.

Abstract

We consider the pseudocritical temperatures for the chiral and deconfinement transitions within a Polyakov-loop Dyson-Schwinger equation approach which employs a nonlocal rank-2 separable model for the effective gluon propagator. These pseudocritical temperatures differ by a factor of two when the quark and gluon sectors are considered separately, but get synchronized and become coincident when their coupling is switched on. The coupling of the Polyakov-loop to the chiral quark dynamics narrows the temperature region of the QCD transition in which chiral symmetry and deconfinement is established. We investigate the effect of rescaling the parameter T_0 in the Polyakov-loop potential on the QCD transition for both the logarithmic and polynomial forms of the potential. While the critical temperatures vary in a similar way, the width of the transition is stronger affected for the logarithmic potential. For this potential the character of the transition changes from crossover to a first order one when T_0 < 210 MeV, but it remains crossover in the whole range of relevant T_0 values for the polynomial form.