A comparative study of type-II, inverse and linear seesaw mechanisms with $ A_{4} $ flavour symmetry

TL;DR

This paper compares type-II, inverse, and linear seesaw models with $A_4$ flavor symmetry to understand neutrino masses, mixings, and charged lepton flavor violation, focusing mainly on linear seesaw computations.

Contribution

It introduces a unified framework incorporating $A_4$ flavor symmetry into various low-scale seesaw models and analyzes their implications for neutrino parameters and lepton flavor violation.

Findings

Neutrino oscillation parameters are constrained using $A_4$ symmetry.

The models predict specific ranges for the lightest neutrino mass and CP phases.

Charged lepton flavor violation decay $oldsymbol{ ext{μ→e+γ}}$ is studied within experimental bounds.

Abstract

We present a comparative analysis of neutrino models based on a broad class of low scale seesaw mechanisms, viz., type II, inverse (ISS) and linear seesaw (LSS) mechanisms that are used to realize the tiny masses of neutrino. In particular, we present their lagrangians with respective particle content. We incorporate $ A_{4} $ flavour symmetry into our models to investigate the light neutrino masses and mixings and flavour structure as well. Apart from it, symmetries like $U(1)_{X}$, $Z_4$ and $Z_5$ to make the models viable are also used. Recent global fit values of neutrino oscillation parameters are used to find the unknown neutrino oscillation parameters such as the lightest neutrino mass and CPV phases (Dirac and Majorana). These unknown parameters can be found by solving a set of simultaneous equations obtained by using $ A_{4} $ product rules in the Lagrangian for different VEV alignments of the triplet flavon field. Finally these data of unknown neutrino oscillation parameters are used to study cLFV (Charged lepton flavour violation) decay $\mu\rightarrow e+\gamma$ and is constrained using their latest bounds and sensitivities. Though we have constructed the models for all type II, ISS and LSS models for the sake of comparison, we focus on computation in LSS in this work. Computations are done up to the tolerance level $<10^{-5}$.