Breaking of the tetra-maximal neutrino mixing pattern

Abstract

We make an attempt to study the present status of the tetra-maximal neutrino mixing (TMM) pattern. It predicts all the three leptonic mixing angles θ13 ≈ 8.4 • , θ12 ≈ 30.4 • , and θ23 = 45 • together with the three CP-violating phases −δ = ρ = σ = 90 • . However, the latest global analysis of neutrino oscillation data prefer relatively higher best-fit value of θ12 as well as non-maximal values of both θ23, δ. In order to explain the realistic data, we study the breaking of TMM pattern. We first examine the breaking of TMM due to renormalization group (RG) running effects and then study the impact of explicit breaking terms. We also examine the effect of RG-induced symmetry breaking on the effective Majorana neutrino mass in neutrinoless double beta decay experiments.

The µ–τ reflection symmetry of Majorana neutrinos *

“…2)] ≃ 8.4 • besides equation (1.18). We find that U 4M can fit current neutrino oscillation data after slight µ-τ reflection symmetry breaking effects are taken into account [62,63]. A number of interesting constant neutrino mixing patterns respecting the µ-τ permutation symmetry have also been proposed and discussed in the literature [10].…”