Flavour and CP predictions from orbifold compactification

TL;DR

This paper presents a six-dimensional orbifold compactification model that naturally generates an A4 family symmetry, accurately predicts fermion mixing parameters, and provides sharp predictions for CP violation and neutrinoless double-beta decay.

Contribution

It introduces a novel six-dimensional orbifold compactification framework that yields an A4 family symmetry and makes precise predictions for fermion mixing and CP violation.

Findings

Reproduces neutrino oscillation parameters with high accuracy

Predicts CP violating phase in leptons as approximately +268°

Sharp prediction for neutrinoless double-beta decay mass parameter (~2.65 meV)

Abstract

We propose a theory for fermion masses and mixings in which an $A_4$ family symmetry arises naturally from a six-dimensional spacetime after orbifold compactification. The flavour symmetry leads to the successful "golden" quark-lepton unification formula. The model reproduces oscillation parameters with good precision, giving sharp predictions for the CP violating phases of quarks and leptons, in particular $\delta^\ell \simeq +268 ^\circ$. The effective neutrinoless double-beta decay mass parameter is also sharply predicted as $\langle m_{\beta\beta}\rangle \simeq 2.65\ meV$.