STUDY OF K-P INTERACTIONS AT 4.1-GEV AND 5.5-GEV/C - FINAL STATES WITH 2 CHARGED PARTICLES AND A VISIBLE LAMBDA

The results described in this paper were obtained from an analysis of bubble-chamber pictures of K-p interactions at incident momenta of 4.1 and 5.5 GeVc. This paper reports the results on quasi-two-body final states, which are observed to be predominantly peripheral. In the final states Λρ, Λω, Λφ, and Y1*+(1385)π-, the exchange mechanisms were investigated in terms of the density-matrix formalism. In general, vector-meson exchange appeared to be dominant, and in particular the decay distributions of the Y1*+(1385)π- final state were in good agreement with the predictions of the Stodolsky-Sakurai model. Several reactions show small backward peaks expected from baryon exchange. The prediction of the independent quark model and other symmetry schemes that the forward cross sections for Λρ0 and Λω production should be equal is well satisfied by the present data. We also report measurements of the properties of various resonant states. We find a mass and width for the Y1*(1695) of M=1700±20 MeV, Γ=130±25 MeV. The dominant decay mode is Λπ+, but limits are placed on other possible channels. © 1969 The American Physical Society.