No abstract

No abstract

No abstract

No abstract

The conventional Born approximation formula for rearrangement collisions is used extensively in both atomic and nuclear physics. This formula contains a direct contribution from the heavy-particle or "core" interaction. A straightforward demonstration shows that for the usual case of a massive core this contribution does not appear, so that the only effect of this interaction is to distort the incident and outgoing waves. Such problems as the "post-prior" discrepancy are clarified.