PUB - Publikationen an der Universität Bielefeld

For photon virtualities of Q^2 \gsim 20 {\rm GeV}^2, the results of the (hard Pomeron) fit in the tensor-Pomeron model provide empirical evidence for the validity of the Color Dipole Picture (CDP). For Q^2 \lsim 20 GeV^2, the CDP yields a parameter-free smooth transition from Q^2 \gsim 20 {\rm GeV}^2 to Q2=0Q^2 = 0Q2=0 photoproduction, in distinction from the tensor-Pomeron model that relies on the additional parameter quantifying the intercept of the soft-Pomeron trajectory. Consistency of the CDP with the perturbative QCD (pQCD) improved parton model implies the prediction of C2=ϵ0≅0.30C_2 = \epsilon_0 \cong 0.30C2​=ϵ0​≅0.30 for the exponent C2C_2C2​ of the energy-squared dependence in agreement with the results of the fits.