Charm Production in Deep Inelastic Lepton-Hadron Scattering

A review is given of the QCD corrections to charm quark production in deep inelastic electron-proton scattering. An outline of the computation of the virtual photon-parton subprocesses, from which one obtains the heavy quark coefficient functions, is given. The dominant production mechanisms are discussed. Further we show that the asymptotic heavy quark coefficient functions, computed in the limit Q^2 >> m^2, can be derived using the operator product expansion technique. Further we present the various schemes proposed in the literature to describe the charm component of the structure function and compare them with the most recent data from the experiments carried out at HERA.