Dual simulation of a Polyakov loop model at finite baryon density: correlations and screening masses

TL;DR

This paper uses a dual formulation of a Polyakov-loop model to compute screening masses at real baryon chemical potential, overcoming the sign problem and providing detailed correlation and phase diagram analysis.

Contribution

It introduces a method to determine screening masses at finite density using a dual model, extending previous phase diagram studies with correlation functions and mean-field comparisons.

Findings

Successful computation of screening masses at real chemical potential.

Comparison between numerical and mean-field results shows good agreement.

Enhanced understanding of the phase diagram at finite density.

Abstract

Computations of screening masses in finite-temperature QCD at finite density are plagued by the sign problem and have been performed so far with an imaginary chemical potential. Here, we use a dual formulation of a Polyakov-loop model which allows the determination of screening masses at real baryon chemical potential. This is a second paper in a series devoted to a detailed study of dual Polyakov-loop models at finite density. While the first paper was mainly devoted to establishing the phase diagram of the model, here we compute correlation functions of the Polyakov loops and the second-moment correlation length at non-zero chemical potential. This enables us to evaluate numerically the screening masses from correlations of the real and imaginary parts of the Polyakov loops. We also compute these masses in the mean-field approximation and compare with numerical results. In addition, we provide a quantitative improvement of the general phase diagram presented in the first paper.