Measuring CP violation and testing factorization in Bd→D∗±D∓ and Bs→D∗±sD∓s decays

We show that the CP-violating phases β and β′ can respectively be determined from the time-dependent measurements of Bd→D∗±D∓ and Bs→D∗±sD∓s decays, whose final states are non-CP eigenstates. The penguin contributions to the mixing-induced interference quantities are expected to be about 4% or smaller. We also point out two observables of O(1), which are pure functions of decay constants and form-factors, for a clean test of the factorization hypothesis in neutral-B decays into two heavy charmed mesons.