Neutrino Masses and Leptogenesis from R Parity Violation

In 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.