Production of hadrons and leptons at high pt and pairs at high mass

The study of particle production at high transverse momentum (pt) and pair production at high mass in energetic collisions between nucleons has been a fruitful area of research for over a decade. The approach goes back to Rutherford and is based on the notion that scattering at high momentum transfer should reveal the internal structure of the scatterers. Nowadays, these processes are analyzed in terms of the parton model and Quantum Chromo-Dynamics (QCD). Previous experiments by this collaboration have confirmed the parton-scattering model of large-pt and high-mass production and have discovered the γ particles and the fifth quark. The present experiment extends these measurements to higher beam energy and improves resolution, particle identification, and luminosity. Besides addressing QCD issues, the data also allow limits to be set on the mass and lifetime of the axion