Measurement of the $B^{-}\to D^0{K}^{*-}$ branching fraction

From a sample of $232\times {10}^6$ $\mathit{{\rm Y}}(4S)\to B\overline{B}$ events collected with the BABAR detector at the PEP-II $B$ Factory in 1999–2004, we measure the $B^{-}\to D^0{K}^{*-}(892)$ decay branching fraction using events where the $K^{*-}$ is reconstructed in the $K_S^0{\pi }^{-}$ mode and the $D^0$ in the $K^{-}{\pi }^{+}$, $K^{-}{\pi }^{+}{\pi }^0$, and $K^{-}{\pi }^{+}{\pi }^{+}{\pi }^{-}$ channels: $\mathcal{B}(B^{-}\to D^0{K}^{*-}(892))=(5.29\pm 0.30(\mathrm{stat})\pm 0.34(\mathrm{syst}))\times {10}^{-4}.$

Figure 1

Distributions of $m_{\mathrm{ES}}$ in the signal region for $B^{-}\to D^0{K}^{*-}$ decays where $D^0\to K^{-}{\pi }^{+}$ (top), $K^{-}{\pi }^{+}{\pi }^0$ (middle), and $K^{-}{\pi }^{+}{\pi }^{-}{\pi }^{+}$ (bottom). The dashed curve indicates the contribution from the combinatorial background and the peaking $B$-background which is estimated from a simultaneous fit to the $D^0$ sideband (not shown).

Figure 2

Acceptance corrected distribution of $\cos {\theta }_H(K^{*-})$. The solid line is a fit to a model which includes $P$-wave and $S$-wave interference as well as combinatorial background. The dotted line shows the combinatorial background estimated from the data.

Figure 3

Invariant mass of $K_s^0{\pi }^{-}$ combinations with all other analysis cuts applied. The solid curve is a Breit-Wigner line shape including detector resolution. The dotted line shows the combinatorial background.