  The recently observed color suppressed B0bar to D0 pi0, D0 eta, D0 eta', Ds+
K-and D0 K0bar decay modes all have rates larger than expected, hinting at the
presence of final state interactions. We study rescattering effects in Bbar to
D P, D Kbar and Dbar Kbar modes in the quasi-elastic approach, which is
extended to accommodate D0 eta' without using U(3) symmetry. The D0bar Kbar
modes are of interest in the determination of the unitarity angle phi3/gamma.
The updated DP data are used to extract the effective Wilson coefficients
a_1^{eff} ~ 0.92, a_2^{eff} ~ 0.22, three strong phases delta ~ 62 deg., theta
~ 24 deg., sigma ~ 127 deg., and the mixing angle tau~2 deg. The values of
delta and theta are close to our previous results. The smallness of tau implies
small mixing of D0 eta1 with other modes. Predictions for D0 K-, D+ K- and D0
K0bar agree with data. The framework applies to Bbar to Dbar Kbar decays, and
rates for D0bar K-, D- K0, Ds- pi0, Ds- eta and Ds- eta' modes are predicted.
  From B- to D0bar K- and D0 K- rates, we find r_B=0.09\pm 0.02.

High Energy Physics - Phenomenology