PUB - Publikationen an der Universität Bielefeld

For photon virtualities of Q(2) greater than or similar to 20 GeV2, the results of the (hard Pomeron) fit in the tensor-Pomeron model in terms of the variables, Q(2), and the virtual-photon-proton energy squared, W-2, provide empirical evidence for the validity of the color dipole picture (CDP). Consistency of the CDP with the perturbative QCD (pQCD) improved parton model implies the prediction of C-2 = epsilon(0) congruent to 0.30 for the exponent C-2 of the energy-squared dependence in agreement with the results of the fits. For Q(2) less than or similar to 20GeV(2), the CDP yields a parameter-free smooth transition from Q(2) greater than or similar to 20 GeV2 to Q(2) = 0 photoproduction, in distinction from the tensor-Pomeron model that relies on the additional parameter quantifying the intercept of the soft-Pomeron trajectory.