Non-zero $\theta_{13}$ from the Triangular Ansatz and Leptogenesis
  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. 
H. B. Benaoum
hep-ph