Investigation of Phase Diagram and Bulk Thermodynamic Properties using PNJL Model with Eight-Quark Interactions

TL;DR

This paper extends the PNJL and NJL models of QCD by including eight-quark interactions to better match lattice QCD results, analyzing their effects on the phase diagram and thermodynamic properties of strongly interacting matter.

Contribution

It introduces eight-quark interaction terms into the PNJL and NJL models, improving the accuracy of phase diagram predictions compared to lattice QCD data.

Findings

Eight-quark interactions shift the critical end point to lower chemical potential and higher temperature.

The extended models show better agreement with lattice QCD results.

Comparison between NJL, PNJL, and lattice data highlights the impact of multiquark interactions.

Abstract

We present the bulk thermodynamic properties and phase diagram of strongly interacting matter in an extension of the 3-flavor NJL and PNJL models of QCD. Using a three momentum cut-off scheme, we have extended the multiquark interaction terms up to eight order so that the stability of the vacuum is ensured in these models. We explore the effects of various combinations of the two eight-quark couplings $g_1$ and $g_2$ and present a comparative study between the NJL and PNJL models as well as Lattice QCD data. The main effect of the eight-quark interaction term is to shift the critical end point in the $T-\mu$ phase diagram to a lower value of $\mu$ and higher value of $T$, thus bringing them closer to Lattice QCD results.