INFLUENCE OF INTERMEDIATE-STATE COULOMB SCATTERING ON THE BEHAVIOR OFTHE 2-PARTICLE SCATTERING-AMPLITUDE AT SMALL MOMENTUM-TRANSFER

The leading singularity as the momentum transfer tends towards zero of the elastic, off-shell, two-particle, Coulomb scattering amplitude is investigated and shown to coincide with that of the second Born appro ximation, independently of whether the intermediate-state Coulomb scat tering is represented by the exact or only by the asymptotic Coulomb G reen function. This indicates that for investigations of this type Cou lomb rescattering in the intermediate state can be neglected. Proofs o f this result are developed in both momentum as well as coordinate spa ce.