Hierarchy sensitivity of NO$\nu$A in light of T2K $\nu_e$ appearance data

Abstract

The $\nu_e$ appearance data of T2K experiment has given a glimpse of the allowed parameters in the hierarchy-$\delta_{CP}$ parameter space. In this paper, we explore how this data affects our expectations regarding the hierarchy sensitivity of the NO$\nu$A experiment. For the favourable combinations of hierarchy and $\delta_{CP}$, the hierarchy sensitivity of NO$\nu$A is unaffected by the addition of T2K data. For the unfavourable combinations, NO$\nu$A data gives degenerate solutions. Among these degenerate solutions, T2K data prefers IH and $\delta_{CP}$ in the lower half plane over NH and $\delta_{CP}$ in the upper half plane. Hence, addition of the T2K data to NO$\nu$A creates a bias towards IH and $\delta_{CP}$ in the lower half plane irrespective of what the true combination is.