Phase structure of finite density QCD with a histogram method

TL;DR

This paper investigates the phase structure of finite density QCD in the temperature-chemical potential plane using a histogram method combined with reweighting and cumulant expansion techniques, providing insights into the nature of the phase transition.

Contribution

It introduces a novel approach combining histogram, reweighting, and cumulant expansion methods to analyze the QCD phase transition at finite density.

Findings

Probability distribution functions reveal the order of the phase transition.

The method effectively incorporates complex phase effects of the quark determinant.

Results suggest specific characteristics of the QCD phase boundary.

Abstract

We study the phase structure of QCD in the $T-\mu$ plane using a histogram method and the reweighting technique by performing phase quenched simulations of two-flavor QCD with RG-improved gauge action and O($a$) improved Wilson quark action. Taking the effects of the complex phase of the quark determinant using the cumulant expansion method, we calculate the probability distribution function of plaquette and phase-quenched determinant as a function of $T$ and $\mu$. We discuss the order of the QCD phase transition consulting the shape of the probability distribution function.