ANALYSIS OF ISOBAR PRODUCTION IN p + p AT 28.5 Bev
P. L. Connolly, Evelyn L. Hart, T. W. Morris, R. S. Panvini, David C. Rahm, C. R. Richardson, Alan M. Thorndike · 1966
The production of isobars at several energies up to -30 BeV in highly peripheral p+p and p+D reactions has been investigated recently with counters and spark chambers.These experiments 1,2 determined the missing-mass spectrum in the reactions p+p = p (fast in the laboratory) + (missing mass), by measuring the momentum of the fast proton.The missing-mass spectrum revealed enhancements which were interpreted as nucleon-pion isobars.An enhancement centered at 41400 MeV was prominent at all energies studied.The only other experimental evidence for a 1400 MeV resonance besides these high-energy proton experiments, comes from 'Ir-N phase-shift 3 analysis.The purpose of our experiment is to study isobar production in a bubble chamber (80" BNL H2 chamber), where it is possible to see the charged decays of the isobars and thus determine the quantum numbers of possible resonant states.We are particularly interested in investigating the 1400 enhancement which, according to the phase shift analysis, should be a P resonance.A total 11 of 75,000 pictures have been taken at 28.5 BeV.To date we have processed approximately 1500 two-prong and 500 four-prong events.Since isobar production seems to be highly 2 peripheral, we have selected our sample by requiring that a