Comparison of Lambda and Sigma0 Threshold Production in Proton-Proton Collisions


Threshold measurements of the associated strangeness production reactions pp->pK+Lambda and pp->pK+Sigma0 are presented. Although slight differences in the shapes of the excitation functions are observed, the most remarkable feature of the data is that at the same excess energy the total cross section for the Sigma0 production appears to be about a factor of 28 smaller than the one for the Lambda particle. It is concluded that strong Sigma0-p final state interactions, and in particular the Sigma-N->Lambda-p conversion reaction, are the likely cause of the depletion for the yield in the Sigma signal. This hypothesis is in line with other experimental evidence in the literature.

Preprint: FZJ-IKP(I)-1998-3 in PostScript format (197kB)
Publication: Phys.Rev.Lett. 83 (1999) 682-685