Hadronic production with a Drell-Yan trigger

The ratio of cross sections for producing fast π+'sand π-'s in association with a massive dilepton should be a strongly varying function of the mass of the pair, reducing at small mass to its value in the absence of a pair. For M/sub mumu/2/s > 0.1, the π+/π- ratio should fall by a factor of 1.7 in the reactions p + p → π + (μ+μ-) + X and p + π- → π + (μ+μ-) + X, rise by a factor of 2.6 in p + π+ → π + (μ+μ-) + X, and fall by about 25% in p + p → π + (μ+ μ-)+ X