Bilarge neutrino mixing and Abelian flavor symmetry

Abstract

We explore two bilarge neutrino mixing Anzätze within the context of Abelian flavor symmetry theories: (BL1) sinâ¡θ 12∼λ, sinâ¡θ13∼λ, sinâ¡θ23∼λ, and (BL2) sinâ¡θ12∼λ, sinâ¡θ 13∼λ, sinâ¡θ23∼1- λ. The first pattern is proposed by two of us and is favored if the atmospheric mixing angle θ23 lies in the first octant, while the second one is preferred for the second octant of θ23. In order to reproduce the second texture, we find that the flavor symmetry should be U(1)×Zm, while for the first pattern the flavor symmetry should be extended to U(1)×Zm×Zn with m and n of different parity. Explicit models for both mixing patterns are constructed based on the flavor symmetries U(1)×Z3×Z4 and U(1)×Z2. The models are extended to the quark sector within the framework of SU(5) grand unified theory in order to give a successful description of quark and lepton masses and mixing simultaneously. Phenomenological implications are discussed. © 2013 American Physical Society.