Perturbative and Nonperturbative Contributions to a Simple Model for   Baryogenesis
  Single field baryogenesis, a scenario for Dirac leptogenesis sourced by a time-dependent scalar condensate, is studied. We compare the creation of the charge asymmetry by the perturbative decay of the condensate with the nonperturbative decay, a process of particle production commonly known in the context of inflation as preheating. The nonperturbative channel dominates when the coupling of the scalar field to leptons is sufficiently large. 
K. R. S. Balaji and Bjorn Garbrecht