NEUTRINO MIXING AND SEE-SAW MECHANISM

Models of neutrino masses are discussed capable of explaining in a nat ural way the maximal mixing between nu(mu) and nu(tau) observed by the Super-Kamiokande Collaboration. For three generations of leptons two classes of such models are found implying: a) Delta m(23)(2) much less than Delta m(12)(2) approximate to Delta m(13)(2) and a small mixing between nu(e) and the other neutrinos, b) Delta m(12)(2) much less tha n Delta m(13)(2) approximate to Delta m(23)(2) and a nearly maximal mi xing for solar neutrino oscillations in vacuum. (C) 1998 Elsevier Scie nce B.V. All rights reserved.