Probing generalized parton distributions with electroproduction of lepton pairs off the nucleon

We evaluate the differential cross section for the electroproduction of lepton pairs off a polarized nucleon target in the generalized Bjorken region to leading power accuracy in hard momentum. We discuss the importance of this process for phenomenology of generalized parton distributions. Special attention is given to the sensitivity of physical observables, i.e., diverse asymmetries, to their dependence on scaling variables that allows us to map directly the functional two-dimensional surface of generalized parton distributions