MASSIVE HADRON PAIR PRODUCTION BY 800 GEV C PROTONS ON NUCLEAR TARGETS

We report data on proton-nucleon collisions obtained on Fermilab exper iment E711, in which high transverse momentum hadrons are produced nea r 90-degrees in the proton-nucleon center of mass forming high mass st ates, using an 800 GeV/c proton beam on targets of beryllium, aluminum , iron, and tungsten. The data presented cover the mass range from 7 t o 15 GeV/c2, the three dihadron charge states + + -, and - -, and part on-parton scattering angles up to costheta = 0.50. We present the dif ferential dihadron cross section, as well as the angular and charge de pendence of the measurement. The cross section as a function of the pa rton-parton scattering angle for the three charge states is shown to v ary linearly with the value of the atomic weight. While the angular di stributions are shown to be independent of the target type, a small de pendence on the charge state of the distributions is observed. The dat a are shown to be in good agreement with extrapolations from previous measurements and phenomenological QCD calculations.