Fermion polarization in sfermion decays as a probe of CP phases in the MSSM

The longitudinal polarization of fermions (tops and taus) produced in sfermion decays to neutralinos or charginos can be a useful tool for the determination of SUSY parameters. We discuss this fermion polarization in the context of the MSSM with complex parameters. We show that the dependence on CP-violating phases can be large and that the fermion polarization may hence be used as a sensitive probe of CP phases in the MSSM.