Ratio ofΛandΣ0Photoproduction Cross Sections; High-Mass Hyperon Resonances

Abstract

The ratio of $\Lambda$ to ${\Sigma }^0$ photoproduction cross sections has been measured to be 1.25±0.15. The measurement was carried out at center-of-mass angles of about 30°; the observed ratio disagrees with predictions of a quark model. In the study of $K^{+}$ photoproduction for photon energies from 4.0 to 6.1 BeV, we obtained evidence for $Y^{*}$ states at 2360 and 2530 MeV.