Investigating Two-zero Textures of Inverse Neutrino Mass Matrix under the Lamp Post of LMA and LMA-D Solutions and Symmetry Realization

TL;DR

This paper explores the phenomenological implications of two-zero textures of the inverse neutrino mass matrix under LMA and LMA-D solutions, identifying allowed textures, their CP violation nature, and implications for neutrinoless double beta decay, with a flavor model realization.

Contribution

It identifies which two-zero textures of the inverse neutrino mass matrix are phenomenologically viable under LMA and LMA-D solutions and proposes a flavor model based on A4 symmetry for realization.

Findings

Seven two-zero textures are phenomenologically allowed.

Five textures are compatible with both LMA and LMA-D and are CP violating.

Most textures predict a lower bound on neutrinoless double beta decay amplitude within experimental reach.

Abstract

In this work we have investigated the phenomenological consequences of two-zero textures of \textit{inverse} neutrino mass matrix ($M_{\nu}^{-1}$) in light of the large mixing angle (LMA) and large mixing angle-\textit{dark} (LMA-D) solutions, later of which originates if neutrinos exhibit non-standard interactions with matter. Out of fifteen possibilities, only seven two-zero textures of $M_{\nu}^{-1}$ are found to be phenomenologically allowed under LMA and/or LMA-D descriptions. In particular, five textures are in consonance with both LMA and LMA-D solutions and are necessarily $CP$ violating while remaining two textures are found to be consistent with LMA solution only. The textures with vanishing (1, 1) element of $M_{\nu}^{-1}$ are, in general, disallowed. All the textures allowed under LMA and LMA-D solutions follow the same neutrino mass hierarchy. Furthermore, textures with vanishing (2, 3) element of $M_{\nu}^{-1}$ are found to be either disallowed or are consistent with LMA description only. We have, also, obtained the implication of the model for $0\nu\beta\beta$ decay amplitude $|M_{ee}|$. For most of the textures the calculated $3\sigma$ lower bound on $|M_{ee}|$ is $\mathcal{O}(10^{-2})$, which is within the sensitivity reach of $0\nu\beta\beta$ decay experiments. We have, also, proposed a flavor model based on discrete non-Abelian flavor group $A_4$ wherein such textures of $M_{\nu}^{-1}$ can be realized within Type-I seesaw setting.