Dyons and Roberge - Weiss transition in lattice QCD

TL;DR

This paper investigates the relationship between dyons, Roberge-Weiss phase transition, and lattice QCD with Wilson fermions at finite imaginary chemical potential, providing numerical evidence linking spectral properties to dyon excitations.

Contribution

It establishes a connection between dyons and the Roberge-Weiss transition in lattice QCD, highlighting the role of dyon excitations in spectral gap phenomena.

Findings

Spectral gap features depend on the $Z_3$ sector of the imaginary chemical potential.

Dyon excitations may be responsible for spectral phenomena observed.

Numerical evidence supports the link between dyons and phase transition properties.

Abstract

We study lattice QCD with $N_f=2$ Wilson fermions at nonzero imaginary chemical potential and nonzero temperature. We relate the Roberge - Weiss phase transition to the properties of dyons which are constituents of the KvBLL calorons. We present numerical evidence that the characteristic features of the spectral gap of the overlap Dirac operator as function of an angle modifying the boundary condition are determined by the $Z_3$ sector of the respective imaginary chemical potential. We then demonstrate that dyon excitations in thermal configurations could be responsible (in line with perturbative excitations) for these phenomena.