The mass splittings for the Majorana neutrinos in the exact solution of a
particular 3-3-1 gauge model are computed here in detail. Since both
sin2θ13≃0 and the mass splittings ratio
rΔ≃0.033 are taken into account, the analytical calculations
seem to predict an inverted mass hierarchy and a mixing matrix with a texture
based on a very close approximation to the bi-maximal mixing. The resulting
formulas for the mass squared differences can naturally accomodate the
available data if the unique free parameter (a) gets very small values
(∼10−15). Consequently, the smallness of the parameter requires
(according to our method) a large breaking scale ∼106−107 TeV
in the model. Hence, the results concerning the neutrino mass splittings may
lead to a more precise tuning in the exact solution of the 3-3-1 model of
interest, being able - at the same time - to recover all the Standard Model
phenomenology and predict the mass spectrum of the new gauge bosons
Z′,X,Y in accordance with the actual data. The minimal absolute mass
in the neutrino sector is also obtained - m0≃0.0035 eV - in the case
of our suitable approximation for the bi-maxcimal mixing.Comment: 10 pages, no figure