Strange-Particle Production inπ+−pCollisions

Strange particles produced in interactions of positive pions with protons have been studied with the Brookhaven 20-in. bubble chamber, which was exposed to ${\pi }^{+}$ beams of 2.35, 2.62, and 2.90 BeV/c. Cross sections are presented and the production of resonances is discussed. The outstanding feature of the multi-particle final states is that they are dominated by $K-\pi$, $K-\overline{K}$, and $Y-\pi$ resonances. The isotopic spin of the $\varphi$ is confirmed to be zero and no evidence is found for a $\varphi$ decay into three pions.