Production of charmonium states in 225 GeV/c π-minus beryllium interactions

This thesis reports on the analysis of data obtained during FNAL experiment E610. The Chicago Cyclotron Magnet Spectrometer was used to perform a study of the hadronic production of charmonium. A 225 GeV/c negative pion beam was incident on a beryllium target. The trigger required a dimuon signature which favored opposite sign muon pairs with a large combined p/sub tau/. A search was then made for chi mesons of the charmonium spectrum by combining J/psi mesons found in the dimuon spectrum with photons detected in a large lead glass shower detector. These events were used to determine the fraction of J/psi s produced from chi s. A psi(3685) signal seen in the dimuon spectrum was used to determine the fraction of J/psi s resulting from psi(3685). Assuming that these are the only particles decaying to J/psi, we obtain the fraction of J/psi s produced directly in hadronic collisions - 0.58 +- 0.09 - which is relevant to the production mechanism for charmonium in strong interactions