On the existence of the critical point in finite density lattice QCD

TL;DR

This paper introduces a method to study phase transitions in finite density lattice QCD by analyzing an effective potential, revealing a first order transition at high density and comparing different chemical potential effects.

Contribution

It presents a novel approach using effective potential analysis to identify the critical point in finite density lattice QCD simulations.

Findings

First order phase transition line at high density for bcm_q/T  2.5

Method successfully detects phase transition nature in lattice QCD

Differences observed between quark and isospin chemical potential effects

Abstract

We propose a method to probe the nature of phase transitions in lattice QCD at finite temperature and density, which is based on the investigation of an effective potential as a function of the average plaquette. We analyze data obtained in a simulation of two-flavor QCD using p4-improved staggered quarks with bare quark mass $m/T = 0.4$, and find that a first order phase transition line appears in the high density regime for $\mu_q/T \simge 2.5$. We also discuss the difference between the phase structures of QCD with non-zero quark chemical potential and non-zero isospin chemical potential.