Multiplicities associated with the production of pions, kaons or protons of high transverse momentum, at the ISR

Abstract In high-energy proton-proton collisions, the mean charged multiplicity M in the central region, associated with a high- P T hadron trigger at 90°, shows a linear dependence on both ln s and P T . M is measured to depend on the type (π ± , K ± , p or p ) of the idenfied high- P T trigger particle.