Hyperon-nucleon final-state interaction in the reaction pp → K +YN

Abstract

The hyperon-nucleon effective mass distribution has been calculated for the reaction pp → K +YN at 2.3 GeV. The calculational scheme is based on the impulse approximation model in which the proton is allowed to dissociate into a kaon-hyperon pair. The hyperon interacts with the second proton via an s-wave separable potential whose parameters have been adjusted to fit hyperon-nucleon scattering data. Our calculation reproduces semi-quantitatively the recent Saclay data for two different models of YN forces. The pp→ K 4YN cross section is rather sensitive to the value of the ratio of the coupling constants g 2 K ΛN / g 2 K σN which enter the KNY vertex. This ratio is the only free parameter whose value when fitted to Saclay data turns out to be smaller than the values inferred from fixed angle KN dispersion relation analyses.