Nonzero ${\theta }_{13}$ and Leptogenesis in a Type-I See-saw Model with $A_4$ Symmetry

Abstract

In the light of recent discovery of nonzero ${\theta }_{13}$, we have analyzed the Altarelli-Feruglio $A_4$ flavor symmetry model extended with additional flavon. The inclusion of the new field leads to the deviation from exact tri-bimaximal neutrino mixing pattern in the context of type-I see-saw by producing a nonzero ${\theta }_{13}$ consistent with the recent experimental results at the leading order. A sum rule for light neutrino masses is also obtained in this context. The set-up constraints the two Majorana phases involved in the lepton mixing matrix in terms of $A_4$ parameter space. We have shown that a nonzero lepton asymmetry can be generated while next-to-leading order contributions to the neutrino Yukawa couplings are considered. The two Majorana phases play crucial role in CP-asymmetry parameter and the involvement of ${\theta }_{13}$ in it, is exercised.

Comments: 29 pages, 11 figures, discussion added, version published in Phys. Rev. D