QED radiative corrections to impact factors

We consider radiative corrections to the electron and photon impact factors . The generalized eikonal representation for the e(+)e(-) scattering amplit ude at high energies and fixed momentum transfers is violated by nonplanar diagrams. An additional contribution to the two-loop approximation appears from the Bethe-Heitler mechanism of fermion pair production with the identi ty of the fermions in the final state taken into account. The violation of the generalized eikonal representation is also related to the charge parity conservation in QED. A one-loop correction to the photon impact factor for small virtualities of the exchanged photon is obtained using the known res ults for the cross section of the e(+)e(-) production during photon-nuclei interactions. (C) 2001 MAIK "Nauka/Interperiodica".