Lepton flavor at the electroweak scale: A complete A4 model

TL;DR

This paper introduces a renormalizable A4 flavor symmetry model at the electroweak scale that explains lepton masses, mixings, and dark matter, with suppressed flavor violation and potential LHC signatures.

Contribution

It presents a novel electroweak scale A4 flavor symmetry model with a unique vacuum alignment mechanism, challenging the high-scale flavor symmetry paradigm.

Findings

Suppressed lepton flavor violating processes

Includes a viable dark matter candidate

Potential explanation for LHC diphoton resonance

Abstract

Apparent regularities in fermion masses and mixings are often associated with physics at a high flavor scale, especially in the context of discrete flavor symmetries. One of the main reasons for that is that the correct vacuum alignment requires usually some high scale mechanism to be phenomenologically acceptable. Contrary to this expectation, we present in this paper a renormalizable radiative neutrino mass model with an A4 flavor symmetry in the lepton sector, which is broken at the electroweak scale. For that we use a novel way to achieve the VEV alignment via an extended symmetry in the flavon potential proposed before by two of the authors. We discuss various phenomenological consequences for the lepton sector and show how the remnants of the flavor symmetry suppress large lepton flavor violating processes. The model naturally includes a dark matter candidate, whose phenomenology we outline. Finally, we sketch possible extensions to the quark sector and discuss its implications for the LHC, especially how an enhanced diphoton rate for the resonance at 125 GeV can be explained within this model.