Corrections to Tribimaximal Mixing from Nondegenerate Phases

Abstract

We propose a seesaw scenario that possible corrections to the tribimaximal pattern of lepton mixing are due to the small phase splitting of the right-handed neutrino mass matrix. we show that the small deviations can be expressed analytically in terms of two splitting parameters(${\delta }_1$ and ${\delta }_2$) in the leading order. The solar mixing angle ${\theta }_{12}$ favors a relatively smaller value compared to zero order value ($35.3^{\circ }$), and the Dirac type CP phase $\delta$ chooses a nearly maximal one. The two Majorana type CP phases $\rho$ and $\sigma$ turn out to be a nearly linear dependence. Also a normal hierarchy neutrino mass spectrum is favored due to the stability of perturbation calculations.

Comments: 19 pages 6 figures, Accepted by Mod. Phy. Lett. A