# Evidence for ${B}^{+}\to {h}_{c}{K}^{+}$ and observation of ${\eta }_{c}\left(2S\right)\to p\overline{p}{\pi }^{+}{\pi }^{-}$

10 July 2019

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 $4.8\sigma$. 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 $\left({3.7}_{-0.9}^{+1.0}{\text{}}_{-0.8}^{+0.8}\right)×{10}^{-5}$; the upper limit for the ${B}^{0}\to {h}_{c}{K}_{S}^{0}$ branching fraction is $1.4×{10}^{-5}$ at 90% C.L. In addition, a study of the $p\overline{p}{\pi }^{+}{\pi }^{-}$ invariant mass distribution in the channel ${B}^{+}\to \left(p\overline{p}{\pi }^{+}{\pi }^{-}\right){K}^{+}$ results in the first observation of the decay ${\eta }_{c}\left(2S\right)\to p\overline{p}{\pi }^{+}{\pi }^{-}$ with $12.1\sigma$ significance. The analysis is based on the $711\text{}\text{}{\mathrm{fb}}^{-1}$ data sample collected by the Belle detector at the asymmetric-energy ${e}^{+}{e}^{-}$ collider KEKB at the $\Upsilon \left(4S\right)$ resonance.

Published in: Physical Review D 100 (2019)