Observation of the baryonic decay ${\bar{B}}^0\to \hat{I}{›}_c^{+}\bar{p}{K}^{-}{K}^{+}$

Abstract

We report the observation of the baryonic decay ${\bar{B}}^0\to \hat{I}{›}_c^{+}\bar{p}{K}^{-}{K}^{+}$ using a data sample of $471\times 10^6$ $B\bar{B}$ pairs produced in $e^{+}{e}^{-}$ annihilations at $\sqrt{s}=10.58\mathrm{GeV}$. This data sample was recorded with the $BABAR$ detector at the PEP-II storage ring at SLAC. We find $\mathcal{B}\left({\bar{B}}^0\to \hat{I}{›}_c^{+}\bar{p}{K}^{-}{K}^{+}\right)=\left(2.5\pm 0.4_{(\text{stat})}\pm 0.2_{(\text{syst})}\pm 0.6_{\mathcal{B}\left(\hat{I}{›}_c^{+}\right)}\right)\times 10^{-5}$, where the uncertainties are statistical, systematic, and due to the uncertainty of the $\hat{I}{›}_c^{+}\to p{K}^{-}\ddot{I}{€}^{+}$ branching fraction, respectively. The result has a significance corresponding to 5.0 standard deviations, including all uncertainties. For the resonant decay ${\bar{B}}^0\to \hat{I}{›}_c^{+}\bar{p}\ddot{I}•$, we determine the upper limit $\mathcal{B}\left({\bar{B}}^0\to \hat{I}{›}_c^{+}\bar{p}\ddot{I}•\right)<1.2\times 10^{-5}$ at $90\%$ confidence level.