Measurement of the Branching Fraction and Polarization for the Decay $B^{-}\to D^{*0}{K}^{*-}$

We present a study of the decay $B^{-}\to D^{*0}{K}^{*-}$ based on a sample of $86\times {10}^6$ ${\rm Y}(4S)\to B\overline{B}$ decays collected with the BABAR detector at the PEP-II asymmetric-energy $B$ Factory at SLAC. We measure the branching fraction $\mathcal{B}(B^{-}\to D^{*0}{K}^{*-})=\mathbf{(}8.3\pm 1.1\mathrm{(}\mathrm{stat}\mathrm{)}\pm 1.0\mathrm{(}\mathrm{syst}\mathrm{)}\mathbf{)}\times {10}^{-4}$, and the fraction of longitudinal polarization in this decay to be ${\Gamma }_L/\Gamma =0.86\pm 0.06\mathrm{(}\mathrm{stat}\mathrm{)}\pm 0.03\mathrm{(}\mathrm{syst}\mathrm{)}$.

Figure 1

Distributions of $m_{\mathrm{ES}}$ for $B^{-}\to D^{*0}{K}^{*-}$: (a) all modes; (b) $D^{*0}\to D^0{\pi }^0$ modes; (c) $D^{*0}\to D^0\gamma$ modes. The dashed lines represent the combinatorial background.

Figure 2

Distributions of (a) $\cos {\theta }_D$ and (b) $\cos {\theta }_K$ for $D^{*0}\to D^0{\pi }^0$. Distributions of (c) $\cos {\theta }_D$ and (d) $\cos {\theta }_K$ for $D^{*0}\to D^0\gamma$. The solid line represents the full fit model, the dashed line represents the transverse component, and the shaded region represents the combinatorial background component.