Logarithmic singularities theorem of mass in electrodynamics quantum massless

We give an explicit example of the use of dimensional regularization to calculate in a unified approach, all the ultraviolet, infrared and mass singularities, by considering the LMS (logarithms of mass singularities) theorem in the frame of massless QED (quantum electrodynamics). In the calculation of the divergent part of the cross section, all singularities are found to cancel provided soft-and hard photon emission are both taken into account.