Phase diagrams in nonlocal PNJL models constrained by Lattice QCD results

TL;DR

This paper uses lattice QCD data to constrain nonlocal PNJL models, examining how the critical endpoint's position in the QCD phase diagram depends on model parameters like vector coupling and Polyakov-loop potential.

Contribution

It introduces lattice QCD constraints into nonlocal PNJL models to study the critical endpoint's location, highlighting the impact of vector coupling adjustments.

Findings

Critical endpoint exists in the phase diagram.

Vector coupling shifts the endpoint to lower temperatures.

Model parameters constrained by lattice data influence phase transition predictions.

Abstract

Based on lattice QCD-adjusted SU(2) nonlocal Polyakov--Nambu--Jona-Lasinio (PNJL) models, we investigate how the location of the critical endpoint in the QCD phase diagram depends on the strenght of the vector meson coupling, as well as the Polyakov-loop (PL) potential and the form factors of the covariant model. The latter are constrained by lattice QCD data for the quark propagator. The strength of the vector coupling is adjusted such as to reproduce the slope of the pseudocritical temperature for the chiral phase transition at low chemical potential extracted recently from lattice QCD simulations. Our study supports the existence of a critical endpoint in the QCD phase diagram albeit the constraint for the vector coupling shifts its location to lower temperatures and higher baryochemical potentials than in the case without it.