Unifying CP violations of quark and lepton sectors

TL;DR

This paper explores a unified approach to CP violation in quark and lepton sectors, proposing a high-energy grand unification framework where a single Dirac CP phase explains observed phenomena.

Contribution

It introduces a model linking CP violation in quarks and leptons through spontaneous symmetry breaking at high energy scales.

Findings

The Dirac phase in the PMNS matrix is approximately -π/2.

The Jarlskog invariant in the CKM matrix is near its maximum.

A unified origin of CP violation is proposed in a grand unification context.

Abstract

A preliminary determination of the Dirac phase in the PMNS matrix is $\dell\approx -\frac{\pi}{2}$. A rather accurately determined Jarlskog invariant $J$ in the CKM matrix is close to the maximum. Since the phases in the CKM and PMNS matrices will be accurately determined in the future, it is an interesting problem to relate these two phases. This can be achieved in a families-unified grand unification if the weak CP violation is introduced spontaneously {\it \`a la} Froggatt and Nielsen at a high energy scale, where only one meaningful Dirac CP phase appears.