LFV in Models with A4 Flavour Symmetry

TL;DR

This paper analyzes models with A4 flavor symmetry that predict neutrino mixing patterns, focusing on low-energy observable effects and constraints on new physics scale and mixing angles.

Contribution

It provides an analysis of A4-based models' predictions for low-energy observables using an effective operator approach, highlighting bounds on new physics scale and mixing angles.

Findings

Indications for the new physics scale M

Upper bound on  of a few percent

Dominance of dim-6 operators in effects

Abstract

The approximated tri-bimaximal mixing observed in the neutrino oscillations is a particular feature of a class of models characterized by the spontaneously broken horizontal flavour symmetry A4. In this paper, it is presented an analysis on the predictions of these models for relevant low-energy observables. In an effective operator approach, these effects are dominated by dim-6 operators, suppressed by the scale M of new physics. Indications for M and an upper bound on \theta_{13} of a few percent are found.