  It is generally assumed that due to factorization of long- and short-distance
dynamics perturbative QCD can be applied to exclusive hadronic reactions at
large momentum transfers. Within such a perturbative approach diquarks turn out
to be a useful phenomenological device to model non-perturbative effects still
observable in the kinematic range accessible by present-days experiments. The
basic ingredients of the perturbative formalism with diquarks, i.e. Feynman
rules for diquarks and quark-diquark wave functions of baryons, are briefly
summarized. Applications of the diquark model to the electromagnetic form
factors of the proton in the space- as well as time-like region,
Compton-scattering off protons, gamma-gamma -> p-pbar, and photoproduction of
Kaons are discussed.
