D^0-D̅^0 mixing at a detectable level requires the presence of new physics and may lead to some observable effects in weak decays of B mesons. We show that CP violation induced by D^0-D̅^0 mixing can manifest itself in the decay-rate asymmetry of B^+_u→ D_L(H)l^+ν^ _l vs B^-_u→ D_L(H)l^-ν̅^ _l. A rephasing-invariant generalization of the Gronau-Wyler approach is made to determine the weak phase shift in B^±_u→ D_L(H)K^±, which is only sensitive to the underlying new physics in D^0-D̅^0 mixing.

more »

... e also demonstrate the possible effect of D^0-D̅^0 mixing on CP violation in decay modes of the type B_d→ D_L(H)+(π^0, ρ^0, etc). Finally the model of four quark families is taken as an example to illustrate how the new physics affects D^0-D̅^0 mixing, B^0_d-B̅^0_d mixing and CP asymmetries in the relevant B decays.