Phases of QCD: Lattice thermodynamics and a field theoretical model

TLDR

Lattice QCD studies of QCD thermodynamics are compared with a generalized Nambu–Jona-Lasinio model that incorporates both deconfinement and chiral symmetry restoration via a Polyakov loop background. We investigate three‑color QCD thermodynamics at finite quark chemical potential. The study uses a PNJL model whose Polyakov‑loop potential parameters are fixed in the pure‑gauge sector, computes the chiral condensate, Polyakov loop, equation of state, pressure difference, and quark number density by minimizing the thermodynamic potential, and then compares these results with lattice QCD data.

Abstract

We investigate three-color QCD thermodynamics at finite quark chemical potential. Lattice QCD results are compared with a generalized Nambu Jona-Lasinio model in which quarks couple simultaneously to the chiral condensate and to a background temporal gauge field representing Polyakov loop dynamics. This so-called PNJL model thus includes features of both deconfinement and chiral symmetry restoration. The parameters of the Polyakov loop effective potential are fixed in the pure-gauge sector. The chiral condensate and the Polyakov loop as functions of temperature and quark chemical potential are calculated by minimizing the thermodynamic potential of the system. The resulting equation of state, (scaled) pressure difference and quark number density at finite quark chemical potential are then confronted with corresponding Lattice QCD data.