High P/sub T/ particle production: results from Fermilab experiment 258

Preliminary results are reported from an experiment just completed at Fermilab by a Chicago-Princeton collaboration. The purpose of the experiment was to measure the production of single charged particles at high p/sub T/ by incident pions. Pions, which contain valence anti-quarks, were used as the projectile in the hope that the basic scattering process could be probed by comparing πp and pp interactions. In particular, the charge and type (e.g., π, K, p or anti p) of particles produced at large p/sub T/ are sensitive to the nature of the constituents which scatter. The experiment described here has good particle identification, and can measure the relative production of the various particle types. These ratios are easier to analyze (as they are essentially systematics-free) than the cross sections; that is why it is possible to present results only weeks after the experiment stopped running