Review of pp production experiment at CERN

Results on pp production experiments at CERN have been reviewed. They show evidence for the inclusive production of the now very controversial S(1936) meson, in photon and proton produced reactions, at small Feynman x values; negative evidence for the narrow (pp pi ) state of 2.95 GeV/c/sup 2/, from two high statistics experiments; a preliminary indication (3 standard deviations effect) for the narrow 2204 MeV state produced backwards in reaction pi /sup +/p to Delta /sup ++/(pp) at 20 GeV/c, but with a cross section approximately 5 times smaller than naively expected. (16 refs).