New constraint from Electric Dipole Moments on chargino baryogenesis in MSSM

A commonly accepted mechanism of generating baryon asymmetry in the minimal supersymmetric standard model (MSSM) depends on the CP violating relative phase between the gaugino mass and the Higgsino mu term. The direct constraint on this phase comes from the limit of electric dipole moments (EDM) of various light fermions. To avoid such a constraint, a scheme which assumes the first two generation sfermions are very heavy is usually evoked to suppress the one-loop EDM contributions. We point out that under such a scheme the most severe constraint may come from a new contribution to the electric dipole moments of the electron, the neutron or atoms via the chargino sector at the two-loop level. As a result, the allowed parameter space for baryogenesis in MSSM is severely constrained, independent of masses of the first two generation sfermions.