Consequences of a unified, anarchical model of fermion masses and mixings

TL;DR

This paper presents a unified model explaining fermion masses and mixings without flavor symmetries, embedding it into a 5D SO(10) GUT, with implications for flavor phenomenology and neutrino mixing.

Contribution

It introduces a novel, symmetry-free approach to fermion mass patterns and embeds it into a higher-dimensional GUT framework, preserving gauge coupling unification.

Findings

Explains second and third family mass and mixing features without flavor symmetries.

Embeds the model in a 5D SO(10) GUT with preserved gauge coupling unification.

Predicts a large atmospheric neutrino mixing angle in a unique way.

Abstract

We show that most features of the mass and mixing pattern of the second and third SM fermion families can be accounted for without making use of flavour symmetries or other types of flavour dynamics. We discuss the implications for flavour phenomenology, in particular for the $\tau\to\mu\gamma$ decay rate, and comment on LFV effects at colliders. We show that the model can be embedded in a full SO(10) supersymmetric GUT in 5 dimensions that preserves the successful MSSM gauge coupling unification prediction for $\alpha_s$. Interesting features of this embedding are i) the connection of one of the hierarchy parameters with the strong coupling assumption, ii) the absence of KK threshold effects on the $\alpha_s$ prediction at one loop, and iii) the shift of the GUT scale up to about $10^{17}\GeV$. Proton decay is under control, also due to the larger GUT scale. A large atmospheric angle for normal hierarchical neutrinos is obtained in an unusual way.