# Observation of ${B}^{+}\to p\overline{\Lambda }{K}^{+}{K}^{-}$ and ${B}^{+}\to \overline{p}\Lambda {K}^{+}{K}^{+}$

07 February 2019

Abstract: We report the study of ${B}^{+}\to p\overline{\Lambda }{K}^{+}{K}^{-}$ and ${B}^{+}\to \overline{p}\Lambda {K}^{+}{K}^{+}$ decays using a $772×{10}^{6}\text{}\text{}B\overline{B}$ pair data sample recorded on the $\Upsilon \left(4S\right)$ resonance with the Belle detector at KEKB. The following branching fractions are measured: $B\left({B}^{+}\to p\overline{\Lambda }{K}^{+}{K}^{-}\right)=\left(4.1{0}_{-0.43}^{+0.45}±0.50\right)×{10}^{-6}$, $B\left({B}^{+}\to \overline{p}\Lambda {K}^{+}{K}^{+}\right)=\phantom{\rule{0ex}{0ex}}\left(3.7{0}_{-0.37}^{+0.39}±0.44\right)×{10}^{-6}$, $B\left({\eta }_{c}\to p\overline{\Lambda }{K}^{-}+c.c.\right)=\left({2.83}_{-0.34}^{+0.36}±0.35\right)×{10}^{-3}$ and $B\left({B}^{+}\to p\overline{\Lambda }\varphi \right)=\phantom{\rule{0ex}{0ex}}\left(\text{}7.95±2.09±0.77\right)×{10}^{-7}$, where c.c. denotes the corresponding charge-conjugation process. The intermediate resonance decays are excluded in the four-body decay measurements. We also find evidence for $B\left({\eta }_{c}\to \Lambda \left(1520\right)\overline{\Lambda }+c.c.\right)=\left(3.48±1.48±0.46\right)×{10}^{-3}$ and $B\left({B}^{+}\to \Lambda \left(1520\right)\overline{\Lambda }{K}^{+}\right)=\left(\text{}2.23±\phantom{\rule{0ex}{0ex}}0.63±0.25\right)×{10}^{-6}$. No significant signals are found for $J/\psi \to \Lambda \left(1520\right)\overline{\Lambda }+c.c.$ and ${B}^{+}\to \phantom{\rule{0ex}{0ex}}\overline{\Lambda }\left(1520\right)\Lambda {K}^{+}$; we set the 90% confidence level upper limits on their decay branching fractions as $<1.80×{10}^{-3}$ and $<2.08×{10}^{-6}$, respectively.

Published in: Physical Review D 99 (2019)