$\mu -\tau$ Reflection Symmetry and Its Explicit Breaking for Leptogenesis in a Minimal Seesaw Model

Abstract

The minimal seesaw framework, embroiling the Dirac neutrino mass matrix $M_D$ and the Majorana neutrino mass matrix $M_R$, is quite successful to explain the current global-fit results of neutrino oscillation data. In this context, we consider most predictive forms of $M_D$ and $M_R$ with two simple parameters, respectively. Considering these matrices, we obtain the low energy neutrino mass matrix under type-I seesaw formalism which obeys $\mu -\tau$ reflection symmetry and predicts ${\theta }_{23}=\pi /4$ and $\delta =\pm \pi /2$. In the given set-up, we also evaluate the Baryon Asymmetry of the Universe (BAU) through successful leptogenesis and find that perturbation of $\mathcal{O}(10^{-2})$ leads to the observed BAU and breaks exactness of the symmetry. Moreover, we also perform various correlation studies among different parameters in the framework of broken symmetry.

Comments: 13 pages, 4 figures, some more discussion added. Version accepted for publication in MPLA