Measurements of the absolute branching fractions of $B^{+}\to X_{c\bar{c}}{K}^{+}$ and $B^{+}\to {\bar{D}}^{(\ast )0}\ddot{I}{€}^{+}$ at Belle

Abstract

We present the measurement of the absolute branching fractions of $B^{+}\to X_{c\bar{c}}{K}^{+}$ and $B^{+}\to {\bar{D}}^{(\ast )0}\ddot{I}{€}^{+}$ decays, using a data sample of $772\times 10^6$ $B\bar{B}$ pairs collected at the $\hat{I}\yen (4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. Here, $X_{c\bar{c}}$ denotes $\hat{I}{\cdot }_c$, $J/\ddot{I}ˆ$, $\ddot{I}{‡}_{c0}$, $\ddot{I}{‡}_{c1}$, $\hat{I}{\cdot }_c(2S)$, $\ddot{I}ˆ(2S)$, $\ddot{I}ˆ(3770)$, $X(3872)$, and $X(3915)$. We do not observe significant signals for $X(3872)$ nor $X(3915)$, and set the 90$\%$ confidence level upper limits: $\mathcal{B}(B^{+}\to X(3872)K^{+})<2.7\times 10^{-4}$ and $\mathcal{B}(B^{+}\to X(3915)K^{+})<2.9\times 10^{-4}$. These represent the most stringent upper limit for $\mathcal{B}(B^{+}\to X(3872)K^{+})$ to date and the first measurement for $\mathcal{B}(B^{+}\to X(3915)K^{+})$. The measured branching fractions for $\hat{I}{\cdot }_c$ and $\hat{I}{\cdot }_c(2S)$ are the most precise to date: $\mathcal{B}(B^{+}\to \hat{I}{\cdot }_c{K}^{+})=(12.3\pm 0.8\pm 0.7)\times 10^{-4}$ and $\mathcal{B}(B^{+}\to \hat{I}{\cdot }_c(2S)K^{+})=(4.9\pm 1.1\pm 0.3)\times 10^{-4}$ , where the first and second uncertainties are statistical and systematic, respectively.

10 pages, 3 figures