  We consider a class of baryogenesis models where the Lagrangian in the
visible sector is Charge-Parity (CP) invariant and a baryon asymmetry is
produced only when quantum statistics is taken into account. The CP symmetry is
broken by matter effects, namely the assumption that the primordial plasma
contains another asymmetric species, such as dark matter. Out-of-equilibrium
baryon number violating decays can then generate an asymmetry through Bose
enhancement and/or Pauli blocking of certain decay channels.
