Production ofKMesons in Three-Body States in Proton-Proton Interactions at 6BeVc

Abstract

Analysis of 9700 events, containing at least one observed neutral or charged decay, produced by $6\ensuremath{-}\frac{\mathrm{BeV}}{c}$ protons in the LRL 72-in. liquid-hydrogen bubble chamber has yielded 1746 examples of the reaction $\mathrm{proton}+\mathrm{proton}\ensuremath{\rightarrow}\mathrm{hyperon}+K\mathrm{meson}+\mathrm{nucleon}$. Production cross sections for these three-body reactions are as follows:$\ensuremath{\sigma}(\ensuremath{\Lambda}{K}^{+}p)=54_{\ensuremath{-}5}^{}{}_{}{}^{+3}$\ensuremath{\mu}b, $\ensuremath{\sigma}({\ensuremath{\Sigma}}^{0}{K}^{+}p)=17_{\ensuremath{-}2}^{}{}_{}{}^{+4}$\ensuremath{\mu}b, $\ensuremath{\sigma}({\ensuremath{\Sigma}}^{+}{K}^{0}p)=26\ifmmode\pm\else\textpm\fi{}4$\ensuremath{\mu}b, $\ensuremath{\sigma}({\ensuremath{\Sigma}}^{+}{K}^{+}n)=57\ifmmode\pm\else\textpm\fi{}7$\ensuremath{\mu}b.Strong ${N}^{*}$ production is observed in all channels. In particular, one or more $T=\frac{1}{2}$ resonant states with mass near 1700 $\frac{\mathrm{MeV}}{{c}^{2}}$, decaying into $\ensuremath{\Lambda}{K}^{+}$, and a $T=\frac{3}{2}$ resonance with mass 1920 $\frac{\mathrm{MeV}}{{c}^{2}}$, decaying into ${\ensuremath{\Sigma}}^{+}{K}^{+}$, are produced. In all cases the data are consistent with a production process dominated by a single-pion-exchange mechanism. No evidence is found for a dibaryon state in either the $\ensuremath{\Lambda}$-proton or $\ensuremath{\Sigma}$-nucleon system.