QCD with a theta-vacuum term: a complex system with a simple complex action

TL;DR

This paper investigates the phase structure of QCD with a theta-vacuum term, analyzing symmetry realization and establishing general results on the model's behavior in this complex system.

Contribution

It provides new insights into the phase structure and symmetry realization of QCD with a theta-vacuum term, combining reanalysis of old questions with general theoretical results.

Findings

Reanalysis of P and CT symmetry realization in QCD

Establishment of general results on phase structure with theta term

Insights into the complex action nature of the system

Abstract

We reanalyze in the first part of this paper the old question of P and CT realization in QCD. The second part is devoted to establish general results on the phase structure of this model in the presence of a $\theta$-vacuum term.