Dalitz plot analyses of $B^0 → D^−D^0K^+$ and $B^+ → øverlineD^0D^0K^+$ decays

We present Dalitz plot analyses for the decays of B mesons to D-D0K+ and D¯0D0K+. We report the observation of the Ds1∗(2700)+ resonance in these two channels and obtain measurements of the mass M(Ds1∗(2700)+)=2699-7+14MeV/c2 and of the width Γ(Ds1∗(2700)+)=127-19+24MeV, including statistical and systematic uncertainties. In addition, we observe an enhancement in the D0K+ invariant mass around 2350-2500MeV/c2 in both decays B0→D-D0K+ and B+→D¯0D0K+, which we are not able to interpret. The results are based on 429fb-1 of data containing 471×106BB¯ pairs collected at the (4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory.