Final state interactions in large transverse momentum lepton and hadron production

It is shown that, in standard parton models, initial and final state interactions do not contribute to the leading asymptotic behaviour of the single particle inclusive cross section for the production of a large p/sub T/ lepton or hadron in hadron-hadron collisions. However, they do have an important effect on the distribution of accompanying small p/sub T/ hadrons: superimposed on the large p/sub T/ event is a 'pionization' distribution characteristic of ordinary hadron-hadron collisions. Thus, for example, the cross section for massive lepton pair production is given simply by the Drell-Yan term, though this does not by itself describe the accompanying final state hadrons. (13 refs).