Nucleon structure effects in photon scattering by nuclei

The influence of internal nucleon structure on photon scattering by nuclei has been expressed in terms of an effective Thompson amplitude. It is found that there is a substantial reduction of the effective nuclear Thompson amplitude due to the finite size and the electric polarizability of the nucleon. The magnetic polarizability of the nucleon leads to a small forward - backward asymmetry of the differential cross section, whose effects might influence the extraction of nuclear M1 and E2 strengths from the interference pattern with the leading E1 multipole. (orig.)