Neutrino mass matrix predicted from the symmetric texture

Within the framework of grand unified theories, we carry out a full analysis of the symmetric texture to determine if such a texture can reproduce bi-large neutrino mixings, which have recently been indicated by solar and atmospheric neutrino experiments. It is found that so far as we adopt a symmetric texture, the so-called Froggatt-Nielsen mechanism does not naturally reproduce two large mixing angles. We find that, in order to obtain such mixing angles, we need to adopt a zero texture. By assuming this zero texture under SO(10), we are able to express the neutrino masses and mixing angles in terms of up quark masses, mt, mc and mu with two adjustable parameters for the right-handed Majorana masses. We also obtain the prediction |Ue3| ≤ 0.11. (author)