High energy factorization predictions for the charm structure function F2^c at HERA

High energy factorization predictions for F2^c are derived using BFKL descriptions of the proton structure function F2 at HERA. The model parameters are fixed by a fit of F2 at small x. Two different approaches of the non perturbative proton input are shown to correspond to the factorization at the gluon or quark level, respectively. The predictions for F2^c are in agreement with the data within the present error bars. However, the photon wave-function formulation (factorization at quark level) predicts significantly higher F2^c than both gluon factorization and a next-leading order DGLAP model.Comment: latex file + 6 encapsulated figures, 28 page

Review of High Energy Diffraction in Real an Virtual Proton Scattering at HERA

The electron-proton collider HERA at DESY opened the door for the study of diffraction in real and virtual photon-proton scattering at center-of-mass energies W up to 250 GeV and for large negative mass squared -Q^2 of the virtual photon up to Q^2 = 1600 GeV^2. At W = 220 GeV and Q^2 = 4 GeV^2, diffraction accounts for about 15% of the total virtual photon proton cross section decreasing to ~5% at Q^2 = 200 GeV^2. An overview of the results obtained by the experiments H1 and ZEUS on the production of neutral vectormesons and on inclusive diffraction up to the year 2008 is presented.Comment: 124 pages, 114 figure