On account of the new neutrino oscillation data signaling a nonzero value for the smallest mixing angle (θz), we present an explicit realization of the underlying U(1) symmetry characterizing the maximal atmospheric mixing angle (θy=π4) pattern with two degenerate masses but now with generic values of θz. We study the effects of the form invariance with respect to U(1), and/or Z3, Z 2 subgroups, on the Yukawa couplings and the mass terms. Later on, we specify θz to its experimental best fit value (∼8o), and impose the symmetry in an entire model which includes charged leptons, and many Higgs doublets or standard model singlet heavy scalars, to show that it can make room for the charged lepton mass hierarchies. In addition, we show for the non-tribimaximal value of θz≠0 within a type-I seesaw mechanism enhanced with flavor symmetry that neutrino mass hierarchies can be generated. Furthermore, lepton/baryogenesis can be interpreted via a type-II seesaw mechanism within a setup meeting the flavor U(1) symmetry.
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|Publication status||Published - Dec 26 2012|
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)