Majorana neutrinos in Double Inverse Seesaw and Δ (54) Flavor Models

This work involves augmenting the Formula: see text flavor symmetry model by incorporating two Standard Model Higgs particles into the Inverse Seesaw mechanism. The mass matrices are discussed numerically in the framework of Formula: see text flavor for Majorana neutrinos. We introduced Vector-like fermions and Weyl fermions, which are gauge singlets in the Standard Model and produces Majorana mass terms. We restrict the undesirable terms in our Lagrangian by using additional symmetry. Due to these additional terms, the mass matrices deviate from the tribimaximal neutrino mixing pattern, resulting in the production of a nonzero reactor angle Formula: see text. We found that the atmospheric oscillation parameter (Formula: see text) occupies the upper octant under the normal hierarchy situation. We also study the CP violation (Formula: see text), Jarlskog invariant parameter (J) and Neutrinoless double-beta decay parameter (Formula: see text) in the parameter space of the normal hierarchy model to see whether they concur with the most recent neutrino observations.