Leptogenesis from neutralino decay with nonholomorphic R-parity violation

In supersymmetric models with lepton-number violation, hence also R-parity violation, it is easy to have realistic neutrino masses, but then leptogene sis becomes difficult to achieve. After explaining the general problems inv olved, we study the details of a model which escapes these constraints and generates a lepton asymmetry, which gets converted into the present observe d baryon asymmetry of the Universe through the electroweak sphalerons. This model requires the presence of certain nonholomorphic R-parity violating t erms. For completeness we also present the most general R-parity violating Lagrangian with soft nonholomorphic terms and study their consequences for the charged-scalar mass matrix. New contributions to neutrino masses in thi s scenario are discussed. (C) 2000 Elsevier Science B.V., Ail rights reserv ed.