Measurements of the absolute branching fractions of $B^{+}\to X_{c\overline{c}}{K}^{+}$ and $B^{+}\to {\overline{D}}^{(*)0}{\pi }^{+}$ at Belle

We present the measurement of the absolute branching fractions of $B^{+}\to X_{c\overline{c}}{K}^{+}$ and $B^{+}\to {\overline{D}}^{(*)0}{\pi }^{+}$ decays, using a data sample of $772\times {10}^{6}B\overline{B}$ pairs collected at the $\mathrm{\Upsilon }(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. Here, $X_{c\overline{c}}$ denotes ${\eta }_c$, $J/\psi$, ${\chi }_{c0}$, ${\chi }_{c1}$, ${\eta }_c(2S)$, $\psi (2S)$, $\psi (3770)$, $X(3872)$, and $X(3915)$. We do not observe significant signals for $X(3872)$ or $X(3915)$ and set the 90% confidence level upper limits at $\mathcal{B}(B^{+}\to X(3872)K^{+})<2.6\times {10}^{-4}$ and $\mathcal{B}(B^{+}\to X(3915)K^{+})<2.8\times {10}^{-4}$. These represent the most stringent upper limit for $\mathcal{B}(B^{+}\to X(3872)K^{+})$ to date and the first limit for $\mathcal{B}(B^{+}\to X(3915)K^{+})$. The measured branching fractions for ${\eta }_c$ and ${\eta }_c(2S)$ are the most precise to date, $\mathcal{B}(B^{+}\to {\eta }_c{K}^{+})=(12.0\pm 0.8\pm 0.7)\times {10}^{-4}$ and $\mathcal{B}(B^{+}\to {\eta }_c(2S)K^{+})=(4.8\pm 1.1\pm 0.3)\times {10}^{-4}$, where the first and second uncertainties are statistical and systematic, respectively.

Figure 1

$M_{\mathrm{bc}}$ distribution for data after the requirement on the $O_{\mathrm{NB}}$. Vertical line shows the lower bound of the selection criteria.

Figure 2

Observed $M_{\mathrm{miss}({\pi }^{+})}$ distribution. Points with error bars represent data. The solid, dashed, and dotted lines represent the total fit result, the contribution from ${\overline{D}}^0$ and ${\overline{D}}^{*0}$, and the contribution from the background, respectively.

Figure 3

Observed $M_{\mathrm{miss}({\mathrm{K}}^{+})}$ distributions:(a) shows the full $M_{\mathrm{miss}({\mathrm{K}}^{+})}$ region, with pull distribution, and (b), (c), (d), and (e) are for zoomed plots for specific $X_{c\overline{c}}$. Points with error bars represent data. Vertical solid lines show the nominal mass of $X_{c\overline{c}}$ included in the fit. Vertical dashed lines show the ones not included in the fit. Solid line represents the total fit result. Dashed and dotted lines are $X_{c\overline{c}}$ contributions and background contributions, respectively.