Testing texture two-zero neutrino mass matrices under current experimental scenario

Abstract

The latest data from Planck collaboration has presented an improved sensitivity limit of the sum of neutrino masses (Σ), Σ < 0.17eV at 95% confidence level (CL). On the other hand, the updated global fits of neutrino oscillation have shown a refined range of atmospheric mixing angle θ 23 at the same CL. In the light of these observations, we have re-investigated the five viable cases ( B 1,2,3,4 and C) of texture two zero Majorana mass matrix in the flavor basis. Using the present Planck's data, we have demonstrated that only cases B 2 and B 4 are now viable for normal mass ordering, while remaining three cases does not meet the present experimental constraints at 2σ CL. The viable cases are also found to be in agreement with the latest T2K, Super-Kamiokande and NOνA results, indicating the preference for normal neutrino mass ordering (m 1 < m 2 < m 3 ), a maximal Dirac CP-violating phase (δ ≃ 270 0 ), and upper octant of neutrino mixing angle (θ 23 > 45 0 ). In addition, the implication of Σ on neutrinoless double beta decay is studied for viable cases.

Texture zeros flavor neutrino mass matrix and triplet Higgs models

“…If neutrinoless double beta decay is observed in future experiments, the A 1 and A 2 cases should be excluded [21,22]. Moreover, Singh shows only B 2 and B 4 are compatible with recent data at 2σ [23]. In this paper, all seven cases of two-zero textures in Eq.…”

Covert symmetries in the neutrino mass matrix

“…We have found that some cases with two-zero textures can indeed be generated by a U (1) symmetry, while others that have also been considered in the literature cannot, at least in the simplest case of two leptonic Higgs doublets. Only one of the matrices with two-zero textures we have found is viable, as it has been confirmed by recent up-to-date numerical analysis [32,33]. Textures with a single vanishing entry are also generated, but none of them are phenomenologically viable.…”

“…It is readily seen that case H is not viable since the structures of m † e m e and of m imply that one lepton flavour does not mix with the others and thus there are vanishing mixings. Structures of type E have two vanishing parameters in m. Neutrino matrices of this type have been thoroughly studied in the literature [32][33][34][35][36][37][38][39][40][41] and it is known that they can yield viable models. More precisely, it is possible to find suitable textures in the sense of specific positions for the zero entries, and specific values for the four non-vanishing parameters that fit well the experimental values for the three mixing angles and two mass squared differences, giving predictions for the remaining parameters.…”

“…Quantitative analysis of two-zero neutrino mass textures have been performed recently in Refs. [32,33], hence we omit this type of structure from our numerical analysis. Let us, however, remark that while published numerical studies generally assume specific textures from the start, here we have identified in a top-down approach which U (1) symmetries can produce such textures Label m † e m em m Viable Comments Table 2.…”

“…Structures of type E with two vanishing parameters can yield viable models. This type of matrices has been already thoroughly analysed in the literature [32][33][34][35][36][37][38][39][40][41], and hence are omitted from our analysis.…”