POMERON STRUCTURE-FUNCTION AND DIFFRACTION DISSOCIATION OF VIRTUAL PHOTONS IN PERTURBATIVE QCD

We study scaling properties of the diffraction dissociation of virtual photons in a deep inelastic scattering. We concentrate on the total diffraction dissociation rate, diffraction excitation mass spectrum and the pomeron structure function to the lowest order in perturbative QCD. We calculate the valence structure function and the strangeness and charm content of the pomeron and estimate the ocean structure function using the pomeron factorization property. We find that quarks carry almost-equal-to 10% of pomeron's momentum. Differential cross section of the (virtual) photon-pomeron scattering is found to exhibit features typical of the hadronic two-body reactions, supporting a treatment of the Pomeron as a particle, whereas the flavor dependence of structure functions does not support the particle treatment of the pomeron. Diffraction dissociation of photons is predicted to make almost-equal-to 15% of the total deep inelastic scattering rate at small x and large Q2. Detailed predictions for the mass spectrum and angular distribution of jets produced on the valence component of the pomeron are presented.