Neutrino masses, baryogenesis and bilinear R-parity violation

We consider the impact of cosmological B-L constraints on supersymmetric standard models without R-parity which can account for the observed atmospheric and solar neutrino masses and mixing. In order to avoid erasing any primordial baryon or lepton asymmetry above the electroweak scale, B-L violation for at least one generation should be sufficiently small. We show that a narrow parameter space of the bilinear model may satisfy such constraints as well as provide the form of the neutrino mass matrix required by current data. (C) 2004 Published by Elsevier B.V.