Search

Transverse momentum distributions of λo, λo, and Ko, produced in pp collisions at x = 0, have obtained at the CERN ISR. The Ko yield is in agreement with published K+, K− results, obtained at this centre-of-mass energy (√s≈44 GeV). The results on λo and λo production obtained in this experiment are compared with results obtained at lower centre-of-mass energies.

A search for high transverse momentum electrons directly produced in proton-proton collisions has been performed at the CERN ISR. The apparatus included a magnetic spectrometer with wire spark chambers, a lead-glass counter array, and a threshold gas Cerenkov counter. At a centre-of-mass energy √s = 52.7 GeV, a signal has been observed in the range 1.6 T ∗ GeV /c . The signal occurs at a level of approximately 10−4 of the inclusive pion cross-section.

The production of high transverse momentum η mesons from proton-proton collisions has been studied at the CERN ISR. The decay η→γγ was identified in an array of lead-glass Cerenkov counters. The preliminary results, obtained at a total centre-of-mass energy √s=52.7 GeV, show an η signal, which amounts to approximately one half of the π0 cross-section for centre-of-mass transverse momenta between 3 and 5 GeV/c. The production of high transverse momentum π0's was also measured and compared with previous results.