Comparison ofΛandΣ0Production near Threshold in Proton-Proton Collisions

Threshold measurements of the associated strangeness production reactions pp→pK+Λ and pp→pK+Σ0 are presented. The most remarkable feature of the data is that at the same excess energy the total cross section for the Σ0 production appears to be about a factor of 28−9+6 smaller than for the Λ particle. It is concluded that strong Σ0p final state interactions, and in particular the ΣN→Λp conversion reaction, are the likely cause of the depletion in the Σ signal. This hypothesis is in line with other experimental evidence in the literature.Received 4 November 1998DOI:https://doi.org/10.1103/PhysRevLett.83.682©1999 American Physical Society