Baryogenesis via B−L violation in SO(10) unified models

We discuss the problem of baryon number generation in the framework of a class of SO(10) grand unified models with an intermediate mass scale. In these theories the neutrino mass spectrum allows for the τ neutrino to be a good candidate for the hot component of the dark matter and, at the same time, an implementation of the MSW mechanism is possible. We show that an adequate matter-antimatter asymmetry is achievable through the interplay of B−L violating decays of scalar bosons into massive right-handed neutrinos with the anomalous B+L violating processes mediated by sphalerons.