Strange-Particle Production in8−BeVcProton-Proton Interactions

Abstract

A systematic survey of strange-particle final states produced by $8-\frac{\mathrm{BeV}}{c}$ protons was made in the BNL 80-in. hydrogen bubble chamber. Cross sections were measured for some 33 reactions. The ratio of the cross section for the $K\overline{K}$ channels to the total strange-particle cross section was measured to be 0.12 and appears to be rising in this momentum region. The total cross section for strange-particle production is estimated as 1.8±0.2 mb. Comparison is made of the data with the predictions of the one-pion-exchange model, and at least partial agreement occurs for the $K^{+}p\Lambda$ and $\pi \mathrm{KN}\Sigma$ final states. The $\mathrm{Kp}\Sigma$ states appear to contain $N^{*}\mathrm{}\left(1924\right)\mathrm{}\to K\Sigma$, and the $\pi \mathrm{KN}\Lambda$ states all include $Y^{*}\mathrm{}\left(1385\right)\mathrm{}$ production with the ${\pi }^{+}{K}^{0}p\Lambda$ state also containing $N^{*}\mathrm{}\left(1236\right)\mathrm{}$ and $K^{*}\mathrm{}\left(890\right)\mathrm{}$ production. An examination of the five- and six-body $K$, $\Lambda$ states indicates strong $Y^{*}\mathrm{}\left(1385\right)\mathrm{}$ and $N^{*}\mathrm{}\left(1236\right)\mathrm{}$ production. Finally, all final states containing a $K$ and a $\Lambda$ show a dependence on $M(K,\Lambda )$ which is well parametrized by a Breit-Wigner shape with $M_0=1777\mathrm{}$ MeV and $\Gamma =345\mathrm{}$ MeV. This behavior is interpreted as being consistent with one-pion exchange as the dominant mechanism for these reactions.