On neutrino and charged lepton masses and mixings: A view from the electroweak-scale right-handed neutrino model

TL;DR

This paper proposes a model within the electroweak-scale right-handed neutrino framework that naturally generates realistic neutrino mixing matrices using an A4 symmetry, while avoiding conflicts with LHC Higgs data.

Contribution

It introduces a novel application of A4 symmetry to the Higgs singlet sector for neutrino mass generation, distinct from charged lepton and quark sectors, explaining differences in mixing matrices.

Findings

Achieves the desired PMNS matrix form with A4 symmetry.

Provides a natural mechanism avoiding LHC Higgs constraints.

Proposes a new approach for neutrino mass sources separate from other fermions.

Abstract

We present a model of neutrino masses within the framework of the EW-$\nu_R$ model in which the experimentally desired form of the PMNS matrix is obtained by applying an $A_4$ symmetry to the \emph{Higgs singlet sector} responsible for the neutrino Dirac mass matrix. This mechanism naturally avoids potential conflict with the LHC data which severely constrains the Higgs sector, in particular the Higgs doublets. Moreover, by making a simple $ans\ddot{a}tz$ we extract $\mathcal{M}_l {\mathcal{M}_l}^\dagger$ for the charged lepton sector. A similar $ans\ddot{a}tz$ is proposed for the quark sector. The sources of masses for the neutrinos are entirely different from those for the charged leptons and for the quarks and this might explain why $U_{PMNS}$ is {\em very different} from $V_{CKM}$.