Connecting Majorana phases to the geometric parameters of the Majorana unitarity triangle in a neutrino mass matrix model

Surender Verma,Shankita Bhardwaj

doi:10.1103/physrevd.97.095022

Surender Verma, Shankita Bhardwaj

Open Access

https://doi.org/10.1103/physrevd.97.095022

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Abstract

We have investigated a possible connection between the Majorana phases and geometric parameters of Majorana unitarity triangle (MT) in two-texture zero neutrino mass matrix. Such analytical relations can, also, be obtained for other theoretical models viz. hybrid textures, neutrino mass matrix with vanishing minors and have profound implications for geometric description of $CP$ violation. As an example, we have considered the two-texture zero neutrino mass model to obtain a relation between Majorana phases and MT parameters that may be probed in various lepton number violating processes. In particular, we find that Majorana phases depend on only one of the three interior angles of the MT in each class of two-texture zero neutrino mass matrix. We have also constructed the MT for class $A$, $B$, and $C$ neutrino mass matrices. Nonvanishing areas and nontrivial orientations of these Majorana unitarity triangles indicate nonzero $CP$ violation as a generic feature of this class of mass models.

Highlights

Recent developments in experimental neutrino physics have catalyzed assiduous efforts to understand the origin of neutrino mass
We have considered a two-texture zero model of neutrino mass matrix and derive possible connection between the Majorana phases and geometric parameters of the Majorana unitarity triangle
We have obtained a possible connection between Majorana phases (ρ, σ) and independent geometric parameters of the Majorana unitarity triangle (MT)

Summary

INTRODUCTION

Recent developments in experimental neutrino physics have catalyzed assiduous efforts to understand the origin of neutrino mass. There are various theoretical constructions to restrict the number of free parameters in the leptonic flavor sector to make a particular model of neutrino masses and mixings more predictive. These approaches include texture zeros [8,9,10,11], hybrid texture [12,13], and vanishing minor [14,15], which are consistent with current data on neutrino masses and mixings. We have considered a two-texture zero model of neutrino mass matrix and derive possible connection between the Majorana phases and geometric parameters of the Majorana unitarity triangle.

TWO-TEXTURE ZEROS NEUTRINO MASS MATRICES

MAJORANA UNITARITY TRIANGLES IN TWO-TEXTURE ZERO MODEL

A2 B1 B2 B3 B4 C

RESULTS AND DISCUSSION

CONCLUSIONS