The basic AB problem is to determine how an unshielded tube of magnetic flux affects arbitrarily long-wavelength charged particles impinging on it. For spin 1 at almost all the particles do not penetrate the tube, so the interaction essentially is periodic in (AB effect). Below-threshold bound states move freely only along the tube axis, and consequent induced vacuum currents supplement rather than screen . For a pure magnetic interaction the tube must be broader than the particle Compton wavelength, i.e., only the nonrelativistic spin- AB problem exists.
- Received 12 September 1996
- Published in the issue dated 15 May 1997
© 1997 The American Physical Society