An estimate for the location of QCD critical end point

TL;DR

This paper proposes using the ratio of shear viscosity to entropy density as a dynamic probe to estimate the location of the QCD critical end point, providing initial estimates for its baryon chemical potential and temperature.

Contribution

It introduces a novel method to estimate the QCD critical end point using the shear viscosity to entropy density ratio as a function of baryon chemical potential and temperature.

Findings

Estimated the CEP at $\mu_B ext{~} 150-180$ MeV and $T ext{~} 165-170$ MeV.

Placed the CEP within reach of current RHIC experiments.

Provided a dynamic probe for locating the QCD critical end point.

Abstract

It is proposed that a study of the ratio of shear viscosity to entropy density $\frac{\eta}{s}$ as a function of the baryon chemical potential $\mu_B$, and temperature T, provides a dynamic probe for the critical end point (CEP) in hot and dense QCD matter. An initial estimate from an elliptic flow excitation function gives $\mu^{\text{cep}}_B \sim 150-180$ MeV and $T_{\text{cep}} \sim 165 - 170$ MeV for the location of the the CEP. These values place the CEP in the range for "immediate" validation at RHIC.