ACCURACY OF RADIATIVE CORRECTIONS TO ELECTROMAGNETIC SCATTERING FROM PROTONS

Present calculations of radiative corrections for electron-proton and positron-proton scattering usually omit various parts independent of an infrared cutoff in two-photon-exchange contributions to the processes. These parts are examined for their effect on simple calculations which accompany the interpretation of experimental measurements. It is concluded that the simple calculations may not be adequate for largeangle scattering. More detailed analytic approximations are given for use at such angles if the asymptotic decrease of proton form factors is at least as fast as t-2. A numerical method is outlined for slower decreases. The contribution of the N*(1236) resonance to radiative corrections is noted to depend most strongly on the choice of a form factor for N* photoproduction. © 1969 The American Physical Society.