GAUGED B-3L(TAU) AND BARYOGENESIS

It has recently been shown that by extending the minimal standard mode l to include a right-handed partner to nu(tau) it is possible to gauge the B - 3L(tau) quantum number consistently. If we add two scalar tri plets, one trivial (xi(1)) and one nontrivial (xi(2)) under B - 3L(tau ), it is possible also to have desirable neutrino masses and mixing fo r neutrino oscillations. At the same time, a lepton asymmetry can be g enerated in the early universe through the novel mechanism of the deca y of the heavier xi(1) into the lighter xi(2) plus a neutral singlet(z eta(0)). This lepton asymmetry then gets converted into a baryon asymm etry at the electroweak phase transition. (C) 1998 Elsevier Science B. V. All rights reserved.