Strange particle production in three- and four-body final states of 16 GeV/c π+p reactions

Three- and four-body final states with strange particles are studied in π+p and π-p interactions at 16 GeV/c. Cross sections are presented and their energy dependence is investigated. Production mechanism, resonance production and quantum number transfer are discussed. Strong Y*(1385) production is found in the reaction π+p→ΛK+π+, while the corresponding π-p reaction is dominated by production of K*(890). In the NKanti Kπ channels, the K and anti K are produced mainly at the same vertex, i.e. non-strangeness exchange ΔS = 0 is dominant (about 75% of the cases), whereas in the ΛKππ channels, the Λ and K are more frequently produced at opposite vertices, i.e. mod(ΔS) = 1 exchange is important (about 60% of the cases). Results on the polarization of the lambdas produced in the π+p reactions are given. (Auth.)