Combining the measured B_s mixing with b \to s\ell^+\ell^- rate data, we find a sizable 4 generation t' quark effect is allowed, for example with m_{ t'} \sim 300 GeV and V_{ t's}^*V_{ t'b} \sim 0.025 e^{ \pm i 70^\circ}, which could underly the new physics indications in CP violation studies of b \to s qbar q transitions. With positive phase, large and negative mixing-dependent CP violation in B_s system is predicted, \sin 2\Phi_{ B_s} \sim -0.5 to -0.7. This can also be probed via width difference methods. As a corollary, the short distance generated D^0-D^0bar mass difference is found to be consistent with, if not slightly higher than, recent B factory measurements, while CP violation is subdued with \sin 2\Phi_D \sim -0.2.
Categories: hep-ph