Resolving Entanglement of CPV Phase with Octant of $\theta _{23}$, and Leptogenesis

Abstract

Present day universe has dominance of matter over antimatter, which can be explained in terms of Baryon Asymmetry of the Universe (BAU). What causes BAU, still continues to excite theorists. Leptogenesis can possibly explain BAU, which needs existence of CPV (CP violation) phase in leptonic sector. CPV phase in leptonic sector in turn is correlated to non zero value of the reactor angle, $\theta _{13}$ which has been determined recently precisely by the Daya Bay experiment. Grand Unified Theories (GUTs) propose very attractive scenarios for neutrino masses and mixings, along with the existence of CPV phase in leptonic sector. In this work, we present some interesting results on CPV and leptogenesis in GUTs. We have analysed the effect of octant degeneracy on leptogenesis. CP assymetry has been found to depend on octant of $\theta _{23}$ (entanglement of $\delta _{\textit{CP}}$ and octant of $\theta _{23}$) as well as on mass hierarchy.