AHARONOV-CASHER EFFECT IN MASSIVE-PHOTON ELECTRODYNAMICS

In concurrence with a recent calculation for the Aharonov-Bohm effect by Boulware and Deser, it is shown that the Aharonov-Casher phase shift for a neutral magnetic dipole diffracted around a uniform infinitely long line charge still occurs in massive-photon electrodynamics. This effect reduces smoothly to the original in the limit that the photon mass vanishes. Unlike the case for the Aharonov-Bohm effect, however, the neutral particle has no classical acceleration regardless of the photon mass. This demonstrates the existence of pure nonlocal effects for nongauge fields. © 1990 The American Physical Society.