An extraction of the skewing factor from DESY-HERA data

in this contribution we present recent investigation on the extraction of the skewing factor, defined as the ratio of the imaginary parts of the amplitudes im ${\cal a}$(g* p ？ g* p)/ im ${\cal a}$(g* p ？ g p). this factor is extracted from the data using the recent dvcs and the inclusive inelastic cross section measurements at desy-hera. we compare the results to the theoretical predictions for nlo qcd and the color dipole approach.