DEEPLY VIRTUAL COMPTON SCATTERING WITHIN THE COLOR DIPOLE APPROACH AND SATURATION MODEL

The deeply virtual Compton scattering (DVCS) is investigated in the color dipole approach, implementing the dipole cross section through the saturation model. The imaginary and real part of the DVCS amplitude are obtained and the results are compared to the available data. The investigation of hard exclusive reactions in the Bjorken limit is a reliable access of obtaining information into details on the structure of the nucleon which could not be obtained considering inclusive deep inelastic processes. The probe provided by the photon works as a clean tool reactions in order to extract reliable knowledge on the substructure of strongly interacting particles complementar to exclusive vector meson production. The recent data from the DESY ep collider HERA on exclusive di®ractive virtual Compton process [1, 2] (DVCS) at large Q2 becomes an important source to study the partons, in particular gluons, inside the proton for nonforward kinematics and its relation with the forward one. These features are encoded in the formalism of the so-called skewed parton distributions [3], where dynamical correlations between partons with di®erent momenta are taken into account. A considerable interest of the DVCS process lies in the particular access it gives to these generalized parton distributions (GDP) through the interference term with the Bethe-Heitler process. The high energy situation at HERA gives the important opportunity to constrain the gluon contribution to GPDs and to study the evolution in virtuality Q2 of the quark and gluon distributions. On the other hand, recently the color dipole formalism has provided a simultaneous description of photon induced process. The inclusive deep inelastic reaction and the photon di®ractive dissociation has been successfully described and the study of othe