CP Violation and the Light Quark Sector

TL;DR

This paper proposes a new framework for understanding CP violation in the light quark sector, linking it to flavor symmetries and quark mass ratios, suggesting maximal CP violation with a near-rectangular unitarity triangle.

Contribution

It introduces a novel description of flavor mixing based on flavor symmetries and clarifies conditions for CP violation related to light quark mass ratios.

Findings

CP violation is primarily linked to a large phase difference in light quarks.

The unitarity triangle is close to a right triangle, indicating maximal CP violation.

CP violation magnitude correlates with light quark mass ratios.

Abstract

In view of the observed strong hierarchy of quark masses, we discuss a new description of flavor mixing which is particularly suited for models of quark mass matrices based on flavor symmetries. The necessary and sufficient conditions for CP violation are clarified. The emergence of CP violation is primarily linked to a large phase difference (near 90^{\circ}) in the light quark sector. The unitarity triangle is determined by the mass ratios of the light quarks. We conclude that the unitarity triangle should be close or identical to a rectangular triangle, and CP violation is maximal in this sense.