Effective Potential and Phase Diagram in the Strong-Coupling Lattice QCD with Next-to-Next-to-Leading Order and Polyakov Loop Effects

TL;DR

This paper studies the interplay of chiral and deconfinement transitions in strong coupling lattice QCD, incorporating next-to-next-to-leading order effects and Polyakov loop dynamics to better understand phase behavior.

Contribution

It introduces a combined approach using advanced effective actions and approximation schemes to analyze phase transitions in lattice QCD with improved accuracy.

Findings

Polyakov loop suppresses chiral condensate.

Chiral transition temperature aligns with Monte Carlo results.

Polyakov effects lower the chiral transition temperature.

Abstract

We investigate chiral and deconfinement transitions in the strong coupling lattice QCD for color SU(3). We combine the leading order Polyakov loop effective action of the strong coupling expansion and the next-to-next-to-leading order (1/g^4) fermionic effective action with one species of unrooted staggered fermion. Two approximation schemes are adopted to evaluate the Polyakov loop effects; a Haar measure method (no fluctuation from the mean field) and a Weiss mean-field method (with fluctuations). The Polyakov loop is found to suppress the chiral condensate and to reduce the chiral transition temperature at mu = 0. The chiral transition temperature roughly reproduces the Monte Carlo results in the region beta = 2N_c /g^2 < 4.