Rapidities of produced particles in 200-GeV/c +/p/K+ interactions on Au, Ag, and Mg

We have used the Fermilab 30-in. bubble chamberhybrid spectrometer to study the rapidities of produced particles in the interactions of 200-GeV/c protons and + and K+ mesons with nuclei of gold, silver, and magnesium. The average rapidity decreases linearly with the number of projectile collisions p (up to p=5) with no A dependence and little beam dependence. The ratio R of normalized rapidity distributions for hadron-nucleus to hadron-proton interactions shows a plateau in the central region, and becomes much larger in the target region. However, the increase is significantly less than has been reported in previous experiments. As a function of p, the ratio R rises linearly in the target region, more gently in the central region, and decreases slowly in the projectile region, in all cases with no A dependence. Some discrepancies with a previous experiment are observed in the central region. Long-range rapidity correlations are observed in hadron-nucleus events, but not in hadron-proton events. For the former, it is shown that the correlations exist only for those events with multiple projectile collisions, as expected in the multichain dual parton model. © 1990 The American Physical Society.