The hard-scattering approach with diquarks

Abstract

The perturbative description of exclusive hadronic reactions in the kinematic region of large transverse momentum transfers is based on factorization of long- and short-distance dynamics. In the present contribution we shortly review the corresponding theoretical framework, the, so called, “hard-scattering approach”. In this context, diquarks can serve as a useful phenomenological device to model non-perturbative effects which are still observable in the kinematic range accessible by present-day-experiments. We outline, how diquarks can be treated within perturbative QCD. As an application of the resulting diquark model the reaction γp→Vp, with V denoting a Φ or a J/ϕ meson, is considered.