CP asymmetry in the Higgs decay into the top pair due to the stop mixing
  We investigate a potentially large CP violating asymmetry in the decay of a neutral scalar or pseudoscalar Higgs boson into the top-anti-top pair. The source of the CP nonconservation is the complex mixing in the (left-right) stop sector. One of the interesting consequence is the different rates of the Higgs boson decays into CP conjugate polarized states. 
Fred Browning, Darwin Chang, and Wai-Yee Keung