Some properties of two Nambu--Jona-Lasinio -type models with inputs from lattice QCD

TL;DR

This paper explores the phase diagram of the Polyakov--Nambu--Jona-Lasinio (PNJL) model at finite temperature and chemical potential, examining the impact of flavor-mixing interactions on the critical end point and connecting QCD with nonlocal NJL models and gluon propagators.

Contribution

It analyzes how flavor-mixing interactions influence the critical end point in the PNJL model and investigates links between QCD, nonlocal NJL models, and gluon propagators.

Findings

The CEP location shifts with flavor-mixing strength.

Weaker flavor-mixing can eliminate the CEP.

Connections between gluon propagator and hadronic phenomenology are proposed.

Abstract

We investigate the phase diagram of the so-called Polyakov--Nambu--Jona-Lasinio (PNJL) model at finite temperature and nonzero chemical potential. The calculations are performed in the light and strange quark sectors ($u$, $d$, $s$), which includes the 't Hooft instanton induced interaction term that breaks the axial symmetry, and the quarks are coupled to the (spatially constant) temporal background gauge field. On one hand, a special attention is payed to the critical end point (CEP). The strength of the flavor-mixing interaction alters the CEP location, since when it becomes weaker the CEP moves to low temperatures and can even disappear. On the other hand, we also explore the connection between QCD, a nonlocal Nambu--Jona-Lasinio type model and the Landau gauge gluon propagator. Possible links between the quenched gluon propagator and low energy hadronic phenomenology are investigated.