Neutrinoless Double Beta Decay and Lepton Flavour Violation in Broken μ − τ Symmetric Neutrino Mass Models

Abstract

We have studied neutrinoless double beta decay and charged lepton flavour violation in broken $\mu-\tau$ symmetric neutrino masses in a generic left-right symmetric model (LRSM). The leading order $\mu-\tau$ symmetric mass matrix originates from the type I (II) seesaw mechanism, whereas the perturbations to $\mu-\tau$ symmetry in order for generation of non-zero reactor mixing angle $\theta_{13}$, as required by latest neutrino oscillation data, originates from the type II (I) seesaw mechanism. In our work, we considered four different realizations of $\mu-\tau$ symmetry, viz. Tribimaximal Mixing (TBM), Bimaximal Mixing (BM), Hexagonal Mixing (HM) and Golden Ratio Mixing (GRM). We then studied the new physics contributions to neutrinoless double beta decay (NDBD) ignoring the left-right gauge boson mixing and the heavy-light neutrino mixing within the framework of LRSM. We have considered the mass of the gauge bosons and scalars to be around TeV and studied the effects of the new physics contributions on the effective mass and the NDBD half life and compared with the current experimental limit imposed by KamLAND-Zen. We further extended our analysis by correlating the lepton flavour violation of the decay processes, $\left(\mu\rightarrow 3e\right)$ and $\left(\mu\rightarrow e\gamma\right)$ with the lightest neutrino mass and atmospheric mixing angle $\theta_{23}$ respectively.