Large transverse momentum processes

Abstract

We present a comprehensive survey of experimental and theoretical work on large transverse momentum processes. Exclusive data and single particle inclusive measurements are summarized and some discussion of multiparticle inclusive data is included. We review many of the predictions of nonparton models including the geometrical, statistical, eikonal and bootstrap approaches. A more detailed discussion is given of the structure of models based on the hard scattering of constituents. The predictions for hadronic and electromagnetic processes based on quark counting rules and the constituent interchange model (CIM) are summarized. We present numerous comparisons with experiment and indicate the framework for the comparison with new experimental data. Recent theoretical progress in the problem of relating short distance structure of hadrons with the asymptotic behavior of form factors and fixed angle amplitudes is also reviewed. We include a brief discussion of the possible influence of new hadronic degrees of freedom on large- pT phenomena. Finally, we attempt to anticipate the type of experiments which will prove decisive in the understanding of this subject.