Studies of proton-proton collisions at the CERN ISR with an identified charged hadron of high transverse momentum at 90°: (I). On forward particles in high-PT reactions☆

Abstract In the course of an experiment to investigate the structure of final states from high-energy proton-proton collisions containing an identified charged hadron of high transverse momentum near 90° in the c.m.s., we have studied correlations between the high- P T trigger particle and forward charged particles. An azimuthal asymmetry is observed for the forward particles. A transverse momentum recoil against the trigger particle is seen, largest at large Feynman x and apparently saturating with increasing trigger momentum. We also observe a flatter P T spectrum for the associated forward particles at 90° in azimuth to the trigger than in normal events. The dependence of the correlations on the quantum numbers of the trigger particle is generally small in this region of phase space.