CP Violation and Flavour Mixings in Orbifold GUTs

TL;DR

This paper explores how orbifold GUT models with universal Yukawa couplings can naturally explain fermion masses and mixings, successfully fitting CKM and PMNS matrices through geometric suppression and phase effects.

Contribution

It introduces a 5D orbifold GUT framework with universal Yukawa strengths, demonstrating a successful fit to fermion mixing data.

Findings

Achieves a good fit for CKM and PMNS matrices

Shows the role of geometric suppression factors in fermion mass hierarchy

Highlights the importance of Yukawa phase structure

Abstract

We address the flavour problem by incorporating the hypothesis of universal strength of Yukawa couplings in the framework of a 5D GUT model compactified on an $S^1/(Z_2 \times Z_2^{\prime})$ orbifold. We show that a quantitatively successful picture of fermion masses and mixings emerges from the interplay between the bulk suppression factors of geometric origin and the phases of the Yukawa matrices. We give an explicit example, where we obtain a good fit for both the CKM and PMNS matrices.