Nature of Roberge-Weiss transition end points for heavy quarks in $N_f=2$ lattice QCD with Wilson fermions

TL;DR

This study investigates the nature of Roberge-Weiss transition end points in $N_f=2$ lattice QCD with Wilson fermions, revealing the locations of tricritical points through extensive simulations and analysis of phase transition indicators.

Contribution

It provides new lattice simulation data on the nature and location of Roberge-Weiss transition end points for heavy quarks in $N_f=2$ QCD with Wilson fermions, identifying the ranges of tricritical points.

Findings

Tricritical points are within the ranges 0.070-0.080 and 0.120-0.140 for the hopping parameter.

Simulations determine the nature of RW transition end points using Binder cumulant and susceptibility.

The study maps the phase structure related to RW transitions in heavy quark regimes.

Abstract

The phase structure of QCD with imaginary chemical potential provides information on the phase diagram of QCD with real chemical potential. With imaginary chemical potential $i\mu_I=i\pi T$, previous studies show that the Roberge-Weiss (RW) transition end points are triple points at both large and small quark masses, and second order transition points at intermediate quark masses. The triple and second order end points are separated by two tricritical ones. We present simulations with $ N_f=2 $ Wilson fermions to investigate the nature of RW transition end points. The simulations are carried out at 8 values of the hopping parameter $\kappa$ ranging from 0.020 to 0.140 on different lattice volumes. The Binder cumulant, susceptibility and reweighted distribution of the imaginary part of Polyakov loop are employed to determine the nature of RW transition end points. The simulations show that the two tricritical points are within the range $0.070-0.080$ and $0.120-0.140$, respectively.