CP violating phases and a solution to the strong CP problem

TL;DR

The paper proposes a novel solution to the strong CP problem by linking the theta angle to the CP violating phase in the CKM matrix, addressing longstanding issues in particle physics.

Contribution

It introduces a new approach connecting the theta angle with CKM phase, supported by theoretical arguments and implications for quark mass matrices.

Findings

Washes out issues related to the strong CP phase

Provides a theoretical justification based on the partition function

Discusses phenomenological implications for quark masses

Abstract

We present a solution to the strong CP problem based on the identification of the theta angle with twice the CP violating phase present in the CKM quark matrix. This solution washes out all the unwanted issues stemming form the strong CP phase and is strongly justified by general theoretical arguments based on the partition function associated to the $\theta$ vacuum. Phenomenological consequences on the quark mass matrices are discussed for this case.