Search for $B^{+}$ meson decay to $a_1^{+}(1260)K^{*0}(892)$

We present a search for the decay $B^{+}\to a_1^{+}(1260)K^{*0}(892)$. The data, collected with the BABAR detector at the SLAC National Accelerator Laboratory, represent $465\times {10}^6$$B\overline{B}$ pairs produced in $e^{+}{e}^{-}$ annihilation at the energy of the $\mathit{{\rm Y}}(4S)$. We find no significant signal and set an upper limit at 90% confidence level on the product of branching fractions $\mathcal{B}(B^{+}\to a_1^{+}(1260)K^{*0}(892))\times \mathcal{B}(a_1^{+}(1260)\to {\pi }^{+}{\pi }^{-}{\pi }^{+})$ of $1.8\times {10}^{-6}$.

Figure 1

Distributions for signal-enhanced subsets (see text) of the data projected onto the fit observables for the decay $B^{+}\to a_1^{+}{K}^{*0}$; (a) $m_{\mathrm{ES}}$, (b) $\Delta E$, (c) $\mathcal{F}$, (d) $m(\rho \pi )$ for the $a_1^{+}$ candidate, (e) $m(K\pi )$ for the $K^{*0}$candidate, (f) ${\mathcal{H}}_{K^{*0}}$, and (g) ${\mathcal{H}}_{a_1^{+}}$. The solid lines represent the results of the fit, and the dot-dashed and dashed lines the signal and background contributions, respectively. These plots are made with requirements (see text) on the ratio of signal to total likelihood, computed without the plotted variable.