Generalized ℤ 2 × ℤ 2 in scaling neutrino Majorana mass matrix and baryogenesis via flavored leptogenesis

Abstract

We investigate the consequences of a generalized ℤ2 × ℤ2 symmetry on a scaling neutrino Majorana mass matrix. It enables us to determine definite analytical relations between the mixing angles θ12 and θ13, maximal CP violation for the Dirac type and vanishing for the Majorana type. Beside the other testable predictions on the low energy neutrino parameters such as ββ0ν decay matrix element |Mee| and the light neutrino masses m1,2,3, the model also has intriguing consequences from the perspective of leptogenesis. With the assumption that the required CP violation for leptogenesis is created by the decay of lightest (N1) of the heavy Majorana neutrinos, only τ -flavored leptogenesis scenario is found to be allowed in this model. For a normal (inverted) ordering of light neutrino masses, θ23 is found be less (greater) than its maximal value, for the final baryon asymmetry YB to be in the observed range. Besides, an upper and a lower bound on the mass of N1 have also been estimated. Effect of the heavier neutrinos N2,3 on final YB has been worked out subsequently. The predictions of this model will be tested in the experiments such as nEXO, LEGEND, GERDA-II, T2K, NOνA, DUNE etc.