Comparative analysis of critical regions for the renormalized quark-meson model with and without Polyakov loop potential

TL;DR

This paper compares critical regions near the critical end point in quark-meson models with and without Polyakov loop potential, analyzing how different treatments of quark loops and meson parameters affect phase diagram features.

Contribution

It introduces a novel on-shell renormalization approach for quark-meson models and examines the impact of quark back reaction and potential forms on critical fluctuations.

Findings

Critical regions are mapped with different meson mass assumptions.

Quark back reaction influences the size of critical regions.

The proximity of the tricritical point to the CEP is quantified.

Abstract

The critical regions enveloping the critical end point (CEP) in the chemical potential-temperature plane of phase diagrams, have been mapped by drawing the contours of the normalized quark number susceptibility in the on-shell renormalized two plus one flavor quark meson model (RQM) and Polyakov loop enhanced renormalized Polyakov quark meson (RPQM) model when sigma meson mass=400 and 500 MeV. The renormalized t Hooft coupling c gets significantly stronger when the meson self energies due to quark loops are computed using the pole masses of mesons and parameters are fixed on shell in the Ref. [141] after consistent treatment of the quark one-loop vacuum fluctuation for the RQM model where the light and strange chiral symmetry breaking strengths also become weaker. The impact of the above novel features on the critical fluctuations have been computed. The improved PolyLog-glue form of the Polyakov loop potential of the Ref. [46], is employed to study the effect of the quark back reaction on critical fluctuations and results are compared with the scenario where quark back reaction is absent in the RPQM model with the Log form of the Polyakov loop potential. Using the large Nc standard chiral perturbation theory inputs,~the phase diagrams are computed in the light chiral limit of zero pion mass and the proximity of the tricritical point (TCP) with the CEP is quantified in the chemical potential-temperature plane.The RQM, RPQM model critical regions are compared with those reported in the Ref. [118] by different treatment of quark one-loop vacuum term where curvature masses of mesons are used to fix the parameters of the quark meson(QM), Polyakov quark meson (PQM) model.