Neutrino mass scale and the mixing angle θ₁₃ for quasidegenerate Majorana neutrinos

Abstract

Considering a general mass matrix for quasidegenerate neutrinos and treating the experimentally known oscillation parameters as inputs, we study the correlation between the degenerate mass scale (m) and the mixing angle θ₁₃. We find that, corresponding to different values of m, there exist upper bounds on θ₁₃, so that a precise determination of the latter in the future may put an upper limit on the former, and vice versa. One can also find a possible correlation between m and a lower bound of θ₁₃, depending on the relative strength of the unperturbed degenerate mass matrix and the perturbation. The possible constraints on the parameters of a few models of quasidegenerate neutrinos are briefly discussed.