Possible effects of D0-D0 mixing in weak B decays

D0-D0 mixing at a detectable level requires the presence of new physics and may lead to some non-trivial effects in weak decays of B mesons. We show that CP violation of the order 10−3 – 10−2 in D0-D0 mixing can give rise to an observable decay-rate asymmetry between Bu+ → Dl(h)l+ν1 and Bu− → Dl(h)l−νl. A rephasing-invariant generalization of the Gronau-Wyler approach is made to determine the weak phase shift in Bu± → Dl(h)K±, which might deviate significantly from the CP-violating phase γ due to the underlying new physics in D0-D0 mixing. We also examine the possible effect of D0-D0 mixing on CP violation in decay modes of the type Bd → Dl(h) + (π0, ϱ0, etc.). Finally the model of four quark families is taken as an example to illustrate how the new physics affects D0-D0 mixing, Bd0-Bd0 mixing and CP asymmetries in the relevant B decays.