QED radiative corrections to virtual Compton scattering - art. no. 025501

The QED radiative corrections to virtual Compton scattering (reaction ep--> ep gamma) are calculated to first order in alpha(em)=e(2)/4 pi. A detailed study is presented for the one-loop virtual corrections and for the first o rder soft-photon emission contributions. Furthermore, a full numerical calc ulation is given for the radiative tail, corresponding to photon emission p rocesses, where the photon energy is not very small compared with the lepto n momenta. We compare our results with existing works on elastic electron-p roton scattering, and show for the ep-->ep gamma reaction how the observabl es are modified due to these first order QED radiative corrections. We show results for both unpolarized and polarized observables of virtual Compton scattering in the low energy region (where one is sensitive to the generali zed polarizabilities of the nucleon), as well as for the deeply virtual Com pton scattering.