Lee-Yang edge singularities in 2+1 flavor QCD with imaginary chemical potential

TL;DR

This paper investigates the Lee-Yang edge singularities in 2+1 flavor QCD with imaginary chemical potential using lattice simulations, aiming to understand phase transitions and locate the critical end point.

Contribution

The study introduces a novel method to locate singularities in the complex chemical potential plane and applies it to QCD with HISQ lattices, connecting results to the 3D Ising model.

Findings

Scaling consistent with Lee-Yang edge singularities near RW transition

Parameters determined using 3D Ising model scaling functions

Preliminary evidence linking singularities to the chiral phase transition

Abstract

We present results of the location of the closest singularities in the complex chemical potential plane using a novel method. These results are obtained with (2+1)-flavor of highly improved staggered quarks (HISQ) on lattices with temporal extent of Nt=4,6. We show that the scaling is consistent with the expected scaling of the Lee-Yang edge singularities in the vicinity of the Roberge-Weiss (RW) transition. We determine various non-universal parameters using 3D Ising model scaling functions that map QCD in the scaling region of the RW transition. Furthermore, as a preliminary result we discuss how the Lee-Yang edge singularity can be used to probe the chiral phase transition in QCD. The singularity obtained close to the chiral phase transition temperature Tc seems to be in agreement with the expected scaling of the Lee-Yang edge singularity. As an outlook, we discuss the scaling of the Lee-Yang edge singularity in the vicinity of a possible critical end point in QCD, at even lower temperatures. In the future, such a scaling analysis might hint on the existence and the location of the critical end point. The work presented here is a part of an ongoing project of Bielefeld Parma joint collaboration.