Non-zero ${\theta }_{13}$ from the Triangular Ansatz and Leptogenesis

Abstract

Recent experiments indicate a departure from the exact Tri-Bimaximal mixing by measuring definitive non-zero value of ${\theta }_{13}$. Within the framework of type I seesaw mechanism, we reconstruct the triangular Dirac neutrino mass matrix from the $\mu -\tau$ symmetric mass matrix. The deviation from $\mu -\tau$ symmetry is then parametrized by adding dimensionless parameters $y_i$ in the triangular mass matrix. In this parametrization of the neutrino mass matrix, the non-zero value ${\theta }_{13}$ is controlled by $\Delta y=y_4-y_6$. We also calculate the resulting leptogenesis and show that the triangular texture can generate the observed baryon asymmetry in the universe via leptogenesis scenario.

Comments: 12 pages, 6 figures, corrected typos