Trimaximal mixing and extended magic symmetry in a model of neutrino mass matrix

Department of Physics and Astronomical Science, Central University of Himachal Pradesh Dharamshala 176215, India

^(a) E-mail: sainilabh5@gmail.com
^(b) E-mail: tapenderphy@gmail.com
^(c) E-mail: monalkashav@gmail.com
^(d) E-mail: s_7verma@hpcu.ac.in (corresponding author)

Received: 10 April 2023
Accepted: 5 June 2023

Abstract

The trimaximal mixing scheme results in “magic” neutrino mass matrix which is known to accommodate neutrino oscillation data. In this paper, we propose a phenomenological ansatz for by extending the magic symmetry that leads to further reduction in the number of free parameters, thereby increasing the predictability of the model. The neutrino mixing parameters, effective Majorana mass m_ee and CP invariants (J_CP, I₁, I₂) are found to exhibit strong correlations for mixing paradigm. One of the generic feature of the model is the requirement of non-maximal for possible CP violation measurable in neutrino oscillation experiments. The observables m_ee and sum of neutrino masses have imperative implications for yet unknown neutrino mass hierarchy. For inverted hierarchy, the lower bound on , predicted by the model, is found to be within the sensitivity reach of the decay experiments. Also, cosmological bound of 0.12 eV on , at 95% CL, refutes inverted hierarchy implying with normal hierarchy as the only viable possibility in the model. We have, also, illustrated a scenario wherein such a construction of the neutrino mass matrix can be realized using symmetry in the framework of Type-I+II seesaw mechanism.