Resonances in Strange-Particle Production

Abstract

In an exposure of propane to 2.0-BeV/c ${\pi }^{-}$ mesons at the Cosmotron in the Columbia 30-in. chamber, reactions have been analyzed for resonances between the particles present in the final state. The reactions studied were sufficiently overdetermined to permit a separation of hydrogen events from carbon. We find definite evidence for resonances in the $\Lambda \pi$ system (${Y_1}^{*}$) with $M_0=1392\mathrm{}\pm 7$ MeV and $\frac{\Gamma }{2}=40\mathrm{}\pm 10$ MeV; in the $K\pi$ system ($K^{*}$) with $M_0=897\mathrm{}\pm 10$ MeV and $\frac{\Gamma }{2}=30\mathrm{}\pm 10$ MeV. We also seem to see the 1404- and 1525-MeV $\Sigma \pi$ resonances. The data indicate that the ${Y_1}^{*}$ has spin $\frac{3}{2}$ and its parity is even.