Observation of $B^{\pm} \to D_{CP}K^{*\pm}$ Decays

Abstract

We report preliminary results on the decay $B^{-} \to D^{0}K^{*-}$, $B^{-} \to D_{CP}K^{*-}$ and its charge c onjugate using a data sample of 95.8 million $B\bar{B}$ pairs recorded at the $\Upsilon(4S)$ resonance with the Belle d etector at the KEKB asymmetric $e^{+}e^{-}$ storage ring. We find the branching fraction for $B^{-} \to D^{0} K^{*-}$ to be ${\cal B} = (5.2 \pm 0.5(stat) \pm 0.6(sys)) \times 10^{-4}$ and the partial-rate charge asymmetries for $B^{-} \rig htarrow D_{CP}K^{*-}$ to be ${\cal{A}}_1 = -0.02 \pm 0.33(stat) \pm 0.07(sys)$ and ${\cal{A}}_2 = 0.19 \pm 0.50(stat) \pm 0.0 4(sys)$ where the indices 1 and 2 represent the CP=+1 and CP=$-$1 eigenstates of the $D^{0}-\bar{D^{0}}$ system, respectively .