LOW-TEMPERATURE BARYOGENESIS AND THE AXION SUPERMULTIPLET

We consider the possibility that the baryon asymmetry is generated at low temperatures as a consequence of the decay of one of the supermultiplet axion companions: the axino or the saxino. We analyse models in which these particles are heavy and decay producing gluinos at temperatures T is similar-to 1 GeV. If CP and B violating couplings for the quark superfields are included, the subsequent decay of these out of equilibrium gluinos can act as seeds for baryogenesis. The most attractive features of this scenario are that the required amount of CP violation is small, well consistent with the bounds on the electric dipole moment of the neutron. and the mechanism works even for low reheating temperatures after inflation (T(RH) greater than of similar to 10(4) GeV).