The role of CP violating scatterings in baryogenesis - case study of the   neutron portal
  Many baryogenesis scenarios invoke the charge parity (CP) violating out-of-equilibrium decay of a heavy particle in order to explain the baryon asymmetry. Such scenarios will in general also allow CP violating scatterings. We study the effect of these CP violating scatterings on the final asymmetry in a neutron portal scenario. We solve the Boltzmann equations governing the evolution of the baryon number numerically and show that the CP violating scatterings play a dominant role in a significant portion of the parameter space. 
Iason Baldes, Nicole F. Bell, Alexander Millar, Kalliopi Petraki,   Raymond R. Volkas
hep-ph