Electric Dipole Moments and Neutrino Mass Models

TL;DR

This paper investigates the flavor structures contributing to electric dipole moments in quarks and leptons, highlighting the significance of rainbow-like processes and their potential correlations with neutrino mass models.

Contribution

It systematically analyzes rainbow-like flavor structures in EDMs across different neutrino mass generation mechanisms, revealing their larger impact compared to invariant structures.

Findings

Rainbow diagrams often dominate EDM contributions.

Rainbow flavor structures are larger and less correlated with invariants.

Study suggests potential correlations between quark and lepton EDMs.

Abstract

While Jarlskog-like flavor invariants are adequate for estimating CP-violation from closed fermion loops, non-invariant structures arise from rainbow-like processes. For the CKM contributions to the quark electric dipole moments (EDMs), or the PMNS contributions to lepton EDMs, the dominant diagrams have a rainbow topology whose flavor structure does not collapse to flavor invariants. Numerically, they are found typically much larger, and not necessarily correlated with, Jarlskog-like invariants. The flavor structures in the quark and lepton sectors are systematically studied, assuming different mechanisms for generating neutrino masses. In addition, the combined study of both Jarlskog-like and rainbow-like flavor structures shed new lights on the possible correlations between quark and lepton EDMs.