HIGH-RESOLUTION STUDY OF HYPERON-NUCLEON INTERACTIONS BY ASSOCIATED STRANGENESS PRODUCTION IN PP COLLISIONS

The associated strangeness production in pp collisions was studied at bombarding energies of 2.3 and 2.7 GeV by detecting the outgoing K+ pa rticles with a high resolution magnetic spectrometer at forward angles up to 23.5-degrees laboratory angle. The kaons were separated from an immense background of protons and pions by a highly resolving TOF ele ctronics in addition to vetoes from Cerenkov detectors utilizing eithe r beta differing Cerenkov light cones in lucite or different threshold s for light production in aerogel. The hyperon-nucleon missing mass sp ectra obtained show strong deviations from pure phase space which is a scribed to final state interations of the pLAMBDA and the NSIGMA syste ms. The structures found are discussed and compared with results from K-d --> pi-YN experiments, with theoretical calculations in the frame of OBE models, and with the prediction of sharp strange dibaryon reson ances from several quark-bag models.