3-flavour lattice QCD at finite density and temperature: QCD at finite isospin density revisited

TL;DR

This study investigates the finite temperature phase transition in 3-flavour lattice QCD at finite isospin density, revealing a revised critical mass estimate and minimal dependence on isospin chemical potential, with no evidence of a critical endpoint.

Contribution

The paper provides a new estimate of the critical mass for the transition and analyzes the dependence of Binder cumulants on simulation parameters, revising previous understandings.

Findings

Critical mass estimate is about 20% lower than previous estimates.

Binder cumulants show little dependence on isospin chemical potential.

No evidence found for a critical endpoint at finite isospin density.

Abstract

We simulate 3-flavour lattice QCD at finite temperature and isospin chemical potential $\mu_I$. In particular we study the nature of the finite temperature transition for quark masses close to the critical mass at which this transition for zero chemical potentials changes from a first order transition to a crossover. We find that the Binder cumulants, used to determine the position of this transition, have very strong dt dependence. This leads us to an estimate of the critical mass which is about 20% below previous estimates. In addition, when this dt dependence is taken into account, we find that the Binder cumulants show very little dependence on mu_I. From this we conclude that we do not as yet see any evidence for the expected critical endpoint. We have argued previously that the position and nature of the finite temperature transition for small mu_I should be the same as that for small quark-number chemical potential mu.