Topological feature and phase structure of QCD at complex chemical potential

TL;DR

This paper explores the topological features and phase structure of QCD at complex chemical potentials, using the analogy of topological order and perturbative expansion to analyze the Roberge-Weiss endpoint and phase diagram.

Contribution

It introduces a novel interpretation of the imaginary chemical potential as an Aharonov-Bohm phase and investigates the Roberge-Weiss endpoint's behavior at small real chemical potentials.

Findings

Roberge-Weiss endpoint defines the pseudo-critical temperature.

Perturbative expansion reveals phase transition behavior.

Proposed QCD phase diagram at complex chemical potential.

Abstract

The pseudo-critical temperature of the confinement-deconfinement transition and the phase transition surface are investigated by using the complex chemical potential. We can interpret the imaginary chemical potential as the Aharonov-Bohm phase, then the analogy of the topological order suggests that the Roberge-Weiss endpoint would define the pseudo-critical temperature. The behavior of the Roberge-Weiss endpoint at small real quark chemical potential is investigated with the perturbative expansion. The expected QCD phase diagram at complex chemical potential is presented.