Large angle Λ° production in exclusive reactions between 3 and 12 GeV/c

The analysis of exclusive neutral strange particle production in the reactions π−p → K°Λ + K°Σ° and pp → ΛΛ + ΛΣ° + c.c. at 3.15, 4.95, 7.9 and 12 GeV/c yielded the differential cross section distributions up to about 90° c.m.s. scattering angle and the Λ-particle polarization at large transverse momentum. Applying a fit to dσ/dt ∞ s−n resulted in n = 8.6 ± 0.9 for the K° Λ + K° Σ° final state which is compatible with the quark counting rule n = 8 for meson-baryon reactions. The average Λ polarization around t = −1.6 (GeV/c)2 was PΛ = 0.79 ± 0.17 at 3.15 GeV/c beam energy.