Study of data on the associated momentum on the trigger side in high p /sub T/ hadron production

The British-French-Scandinavian collaboration has recently studied the non trigger charged mean momentum in different rapidity regions on the trigger hemisphere, (p/sub x/), in the collision of two hadrons at the CERN Intersecting Storing Rings (ISR). In particular, they give for the rapidity regions mod y mod <0.5 and mod y mod <1 the values for the slope, alpha , of (p/sub x/) with the trigger momentum, p/sub T //sup t/. Several authors have analysed those values of alpha in the framework of hard scattering models which predict values independent of p/sub T//sup t/ for (z/sub c/), the longitudinal momentum fraction of the outgoing hard scattered system taken by the trigger. From this analysis they give estimates of (z/sub c/) of very difficult reconciliation with those calculated in the Feynman, Field and Fox (1977) hard scattering model or in the QCD treatment of high p/sub T/ hadron production. The authors have looked for, and found, other data whose model independent analysis is more feasible than that of the data mentioned above. More specifically, they analyse in the framework of the hard scattering models, but otherwise model independently, data on (p/sub x/) in two other rapidity regions ( mod y mod <3, 2< mod y mod <3) and find that consistence of the average slopes, alpha , in these two regions is only achieved with mean values of (z/sub c/) significantly increasing with p/sub T//sup t/ and close in value to those obtained by Feynman et al. (26 refs).