Photoproduction and electroproduction of charm at high energies

We estimate the differential and total cross sections for both the photoproduction of a vector D* meson and its yield in deep inelastic scattering at the DESY HERA collider in the framework of a model motivated by perturbative calculations in QCD. The offered model allows us to take into account higher twists over the transverse momentum of meson at pT~mc and to correctly approach the dominance of c-quark fragmentation at pTmc. We consider the possibility for the hadronization of a color-octet cq̄ state into the meson. The combined contribution by the singlet and octet-color terms results in a good agreement with the experimental data for both the photoproduction and production in deep inelastic scattering.