Observation of $B$ meson decays to $\omega K^{*}$ and improved measurements for $\omega \rho$ and $\omega f_0$

We present measurements of $B$ meson decays to the final states $\omega K^{*}$, $\omega \rho$, and $\omega f_0$, where $K^{*}$ indicates a spin 0, 1, or 2 strange meson. The data sample corresponds to $465\times {10}^6$ $B\overline{B}$ pairs collected with the BABAR detector at the PEP-II $e^{+}{e}^{-}$ collider at SLAC. $B$ meson decays involving vector-scalar, vector-vector, and vector-tensor final states are analyzed; the latter two shed new light on the polarization of these final states. We measure the branching fractions for nine of these decays; five are observed for the first time. For most decays we also measure the charge asymmetry and, where relevant, the longitudinal polarization $f_L$.

Figure 1

Projections for $B^{+}\to \omega {\rho }^{+}$: (a) $\Delta E$, (b) $\mathcal{F}$, (c) $m_{3\pi }$, (d) ${\mathcal{H}}_{\omega }$, and (e) ${\mathcal{H}}_{\pi \pi }$. Points with errors represent data and solid curves represent the full fit functions. Also shown are signal (blue dashed line), $b\to c$ background (magenta dotted-dashed line), and total background (black long-dashed-dotted line). Charmless background and nonresonant background are too small to be seen. To suppress background, the plots are made with requirements on $\ln \mathcal{L}$ that have an efficiency for signal of (40–60)% depending on the plot.

Figure 2

$B$-candidate $m_{\mathrm{ES}}$ projections for (a) $\omega K^{*0}$, (b) $\omega K^{*+}$, (c) $\omega {\rho }^0/\omega f_0$, and (d) $\omega {\rho }^{+}$. The solid curve is the fit function, the black long-dashed-dotted curve is the total background, and the blue dashed curve is the total signal contribution. For (a),(b) we also show the signal components: $K^{*}(892)$ (red dashed line), $(K\pi {)}_0^{*}$ (green dotted line), and $K_2^{*}(1430)$ (magenta dotted-dashed line). We show for (c),(d) the $b\to c$ background (magenta dotted-dashed line), and for (c) the $B^0\to \omega {\rho }^0$ (red dashed line) and $B^0\to \omega f_0$ (green dotted line) components. The plots are made with a requirement on $\ln \mathcal{L}$ that has an efficiency of (40–60)% depending on the plot.

Figure 3

$B$-candidate $K\pi$ mass projections for (a) $\omega K^{*0}$ and (c) $\omega K^{*+}$, and $\pi \pi$ mass projections for (b) $\omega {\rho }^0/\omega f_0$ and (d) $\omega {\rho }^{+}$. The efficiency range and description of the curves are the same as for Fig. 2.

Figure 4

$B$-candidate $K\pi$ helicity projections for (a) $\omega K^{*0}$ and (b) $\omega K^{*+}$. The efficiency range and key for the curves are the same as for Figs. 2 and 2.