English

Neutrino masses and mixing from flavour antisymmetry

High Energy Physics - Phenomenology 2016-01-27 v1

Abstract

We discuss consequences of assuming (ii) that the (Majorana) neutrino mass matrix MνM_\nu displays flavour antisymmetry, SνTMνSν=MνS_\nu^T M_\nu S_\nu=-M_\nu with respect to some discrete symmetry SνS_\nu contained in SU(3)SU(3) and (iiii) SνS_\nu together with a symmetry TlT_l of the Hermitian combination MlMlM_lM_l^\dagger of the charged lepton mass matrix forms a finite discrete subgroup GfG_f of SU(3)SU(3) whose breaking generates these symmetries. Assumption (ii) leads to at least one massless neutrino and allows only four textures for the neutrino mass matrix in a basis with a diagonal SνS_\nu if it is assumed that the other two neutrinos are massive. Two of these textures contain a degenerate pair of neutrinos.Assumption (iiii) can be used to determine the neutrino mixing patterns. We work out these patterns for two major group series Δ(3N2)\Delta(3 N^2) and Δ(6N2)\Delta(6 N^2) as GfG_f. It is found that all Δ(6N2)\Delta(6 N^2) and Δ(3N2)\Delta(3 N^2) groups with even NN contain some elements which can provide appropriate SνS_\nu. Mixing patterns can be determined analytically for these groups and it is found that only one of the four allowed neutrino mass textures is consistent with the observed values of the mixing angles θ13\theta_{13} and θ23\theta_{23}. This texture corresponds to one massless and a degenerate pair of neutrinos which can provide the solar pair in the presence of some perturbations. The well-known groups A4A_4 and S4S_4 provide examples of the groups in respective series allowing correct θ13\theta_{13} and θ23\theta_{23}. An explicit example based on A4A_4 and displaying a massless and two quasi degenerate neutrinos is discussed.

Keywords

Cite

@article{arxiv.1506.00455,
  title  = {Neutrino masses and mixing from flavour antisymmetry},
  author = {Anjan S. Joshipura},
  journal= {arXiv preprint arXiv:1506.00455},
  year   = {2016}
}

Comments

22 pages, 1 figure