Evidence for $B^{+}\to h_c{K}^{+}$ and observation of $\hat{I}{\cdot }_c(2S)\to p\bar{p}\ddot{I}{€}^{+}\ddot{I}{€}^{-}$

Abstract

A search for the decays $B^{+}\to h_c{K}^{+}$ and $B^0\to h_c{K}_S^0$ is performed. Evidence for the decay $B^{+}\to h_c{K}^{+}$ is found; its significance is $4.8\ddot{I}ƒ$. No evidence is found for $B^0\to h_c{K}_S^0$. The branching fraction for $B^{+}\to h_c{K}^{+}$ is measured to be $(3.7_{-0.9}^{+1.0}{}_{-0.8}^{+0.8})\times 10^{-5}$; the upper limit for the $B^0\to h_c{K}_S^0$ branching fraction is $1.4\times 10^{-5}$ at $90\%$ C.L. In addition, a study of the $p\bar{p}\ddot{I}{€}^{+}\ddot{I}{€}^{-}$ invariant mass distribution in the channel $B^{+}\to (p\bar{p}\ddot{I}{€}^{+}\ddot{I}{€}^{-})K^{+}$ results in the first observation of the decay $\hat{I}{\cdot }_c(2S)\to p\bar{p}\ddot{I}{€}^{+}\ddot{I}{€}^{-}$ with $12.1\ddot{I}ƒ$ significance. The analysis is based on the 711 ${\mathrm{fb}}^{-1}$ data sample collected by the Belle detector at the asymmetric-energy $e^{+}{e}^{-}$ collider KEKB at the $\hat{I}\yen (4S)$ resonance.

16 pages, 7 figures