Radiative corrections for electron-proton elastic scattering taking into account high orders and hard-photon emission

We investigate the effect of high-order radiative corrections in unpolarized electron proton elastic scattering and compare with the calculations at lowest order, which are usually applied to experimental data. Particular attention is devoted to the ɛ dependence of radiative corrections, which is directly related to the electric-proton form factor. We consider in particular the effects of the interference terms for soft- and hard-photon emission. The contribution from the emission of a hard photon from the scattered electron should be taken into account. The interference of this term with initial electron and proton emission is also important in leading and next to leading approximation. All these contributions may compensate each other in particular kinematical conditions.