Bottom-up approach to texture zeros in the neutrino mass matrix

Abstract

We investigate one and two texture zeros in the neutrino mass matrix using the latest oscillation data through a bottom-up approach. In this context, we begin by estimating the detailed features of each matrix element by varying the CP violating phases within $(0,\,2\pi)$, the lowest neutrino mass within $(0,\,1)\,{\rm eV}$ and the neutrino oscillation parameters such as three mixing angles and the two mass squared differences within $3\sigma$ of their central values. We find that for normal ordering, only $ee$, $e\mu$ and $e\tau$ elements of the mass matrix can vanish, whereas, for inverted ordering, five elements -- $e\mu$, $e\tau$, $\mu\mu$, $\mu\tau$ and $\tau\tau$ -- can vanish. For two texture zeros, only $(ee,\, e\mu = 0)$ and $(ee,\, e\tau =0)$ are allowed in case of normal ordering. For a particular vanishing element, we also estimate the range of the lowest neutrino mass and the CP violating phases. In particular, very interesting correlation among the CP violating phases and the lowest neutrino mass is obtained for each vanishing cases.