2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/39831In R parity violating supersymmetry (conserving baryon number B but violating lepton number L), Majorana neutrino masses may arise at tree level, in one loop, and in two loops. The L violating interactions work together with the B + L violating electroweak sphalerons to erase any preexisting B or L asymmetry of the Universe. To have successful leptogenesis nevertheless, a specific scenario is proposed.11 pages, no figure, preprint version of talk at DARK 2000, Heidelberg, Germany (July 2000)High Energy Physics - Phenomenologytext