Strange-Particle Production by 3-BeV/cπ−Mesons in Hydrogen

Over 600 strange-particle events were identified on the basis of both kinematical fitting and bubble-density information. The center-of-mass angular distributions generally show the familiar backward tendency for the baryons and forward tendency for the $K$ mesons. Invariant mass distributions show the production of several resonant states including the ${Y_1}^{*}\left(1385\mathrm{} \mathrm{MeV}\right)$, $K^{*}\left(885\mathrm{} \mathrm{MeV}\right)$, and ${Y_0}^{*}\left(1405\mathrm{} \mathrm{MeV}\right)$. The two-body reactions ${\pi }^{-}+p\to K^{*}+{Y_1}^{*}$ and ${\pi }^{-}+p\to K^{*}+{Y_0}^{*}$ are also reported and studied. The two-, three-, and four-particle reactions are discussed and an attempt is made to put limits on the $S{U}_3$ multiplet of the $f^0$ from the number of ${K_1}^0{K_1}^0$ events with a mass near the $f^0$. The cross sections are calculated and the total strange-particle cross section at this energy is estimated to be $\sigma =(1.68\mathrm{}\pm 0.20)$ mb.