Single spin asymmetries in elastic electron-nucleon scattering

We discuss the target and beam normal spin asymmetries in elastic electron-nucleon scattering which depend on the imaginary part of two-photon exchange processes between electron and nucleon. In particular, we estimate these transverse spin asymmetries for beam energies below 2 GeV, where thetwo-photon exchange process is dominated from the resonance contribution to the doubly virtual Compton scattering tensor on the nucleon.