Spontaneous breaking of the flavor symmetry avoids the strong CP problem

TL;DR

This paper proposes that spontaneous breaking of flavor symmetry explains the absence of CP violation in strong interactions, linking flavor symmetry breaking to the strong CP problem.

Contribution

It introduces a model where spontaneous flavor symmetry breaking naturally avoids the strong CP problem, offering a new perspective on flavor physics and CP conservation.

Findings

Flavor symmetry breaking aligns with observed quark masses and mixings.

The approach provides a natural explanation for CP conservation in QCD.

The scalar potential minimization leads to CP-conserving vacuum configurations.

Abstract

A promising approach to the Standard Model flavor puzzle is based on the idea that the $SU(3)^3$ quark-flavor symmetry is spontaneously broken by vacuum expectation values of `Yukawa fields' which minimize the symmetry invariant scalar potential at configurations corresponding to the observed quark masses and mixing angles. We show that this approach provides a simple and elegant explanation for CP conservation in strong interactions.