The critical line of QCD with four degenerate quarks

TL;DR

This paper uses high-statistics Monte Carlo simulations to analyze the pseudo-critical line of QCD with four degenerate quarks at imaginary chemical potential, revealing deviations from quadratic dependence and discussing implications for real chemical potential extrapolations.

Contribution

It provides the first detailed analysis of the pseudo-critical line at imaginary chemical potential for four-flavor QCD, highlighting deviations from quadratic behavior.

Findings

Deviations from quadratic dependence on chemical potential.

High-precision determination of pseudo-critical couplings.

Implications for extrapolation to real chemical potential.

Abstract

We determine the pseudo-critical couplings at imaginary chemical potentials by high-statistics Monte Carlo simulations of QCD with four degenerate quarks at non-zero temperature and baryon density by the method of analytic continuationan. We reveal deviations from the simple quadratic dependence on the chemical potential visible in earlier works on the same subject. Finally, we discuss the implications of our findings for the shape of the pseudo-critical line at real chemical potential, comparing different possible extrapolations.