  We examine diffractive proton-proton scattering p p -> p X and photo- and
electroproduction of \rho^0 mesons \gamma^(*) p -> \rho^0 X, where X denotes a
proton or a final state, into which the proton can go by diffractive
dissociation. Using a functional integral approach we derive the scattering
amplitudes, which are governed by the expectation values of light-like
Wegner-Wilson loops, which are then evaluated using the model of the stochastic
vacuum. For the proton, we assume a quark-diquark structure. From the
scattering amplitudes we calculate total and differential cross sections for
high centre of mass energy and small momentum transfer and compare with
experiments. Furthermore we calculate isovector form factors for the proton and
the pion within the same model.
