On the analytic continuation of the critical line

TL;DR

This paper investigates the systematic effects in analytically continuing the critical line from imaginary to real chemical potential, using a sign-problem-free theory and discussing implications for real QCD.

Contribution

It provides a numerical analysis of the systematic uncertainties in the analytic continuation method applied to the critical line in finite density QCD-like theories.

Findings

Results demonstrate the impact of systematic effects on the critical line determination.

Analysis in a sign-problem-free theory offers insights relevant to real QCD.

Comments on general features applicable to finite baryon density QCD.

Abstract

We perform a numerical study of the systematic effects involved in the determination of the critical line at real baryon chemical potential by analytic continuation from results obtained at imaginary chemical potentials. We present results obtained in a theory free of the sign problem, three-color QCD with finite isospin chemical potential, and comment on general features which could be relevant also to the continuation of the critical line in real QCD at finite baryon density.