High-p T lepton pair production at ep colliders: comparison between various production mechanisms

High-p _T lepton pair production under the conditions of HERA is studied in order to compare the respective contributions of several different production mechanisms, among them the γγ and the Drell-Yan effects. Various distributions are considered. It is shown that the γγ process systematically and largely dominates. Therefore this type of experiment may allow one to determine the equivalent-photon spectrum of the proton.