CPtransformed mixedμτantisymmetry for neutrinos and its consequences

Abstract

We propose a complex extension of mixed µτ antisymmetry in the neutrino Majorana mass matrix M ν . This can be implemented in the Lagrangian by a generalized CP transformation (labeled by a mixing parameter θ) on the left-chiral flavor neutrino fields. We investigate its implications for leptonic CP violation and neutrino phenomenology in general. Interestingly, the µτ mixing parameter θ gets correlated with the Dirac CP phase δ and the atmospheric mixing angle θ 23 through an analytical relation. In general, for arbitrary θ, both θ 23 and δ are nonmaximal. We discuss the corresponding results for the CP asymmetry parameter A µe in neutrino oscillation experiments. For a nonmaximal δ, one of the two Majorana phases is different from 0 or π, thereby leading to nonvanishing Majorana CP violation with observable consequences for the neutrinoless double beta (ββ0ν) decay process. We numerically work out in detail the predictions for that process in relation to various ongoing and forthcoming experiments. We also work out the predictions of our scheme on flavor flux ratios at neutrino telescopes. While exact CP transformed µτ interchange antisymmetry (θ = π/2) leads to an exact equality among those ratios, taking a value 0.5, a tiny deviation can cause a drastic change in them. Careful measurement of these flux ratios in future will further constrain the parameter θ.

Flavoured leptogenesis and CPμτ symmetry

“…To make CP µτ more predictive, a sizable body of work exists to combine flavour symmetries with CP symmetries, despite this being a non-trivial task [23,24]. Several aspects of CP µτ and its alternative versions have also been explored [45][46][47][48][49][50][51][52][53][54].…”

Lepton Flavour Symmetries

“…See(Joshipura and Patel, 2015;Mohapatra and Nishi, 2015;Nishi et al, 2018;Rodejohann and Xu, 2017;Sinha et al, 2019;Zhao, 2017;Zhou, 2014) for more recent applications related to the topic of this section.…”

Diagonal reflection symmetries and universal four-zero texture

“…The discovery of the neutrino oscillation [1][2][3][4] proved finite mass and mixing of neutrinos. In order to explain the peculiar mixing pattern, a lot of flavor structures such as four-zero texture [5][6][7][8][9][10][11], democratic texture , µ−τ symmetry [41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59] and µ−τ reflection symmetry [60][61][62][63][64][65][66][67][68][69][70][71][72][73][74][75][76][77][78][79] have been studied. Among them, the author discussed exact µ − τ reflect...…”