Scalar Aharonov-Bohm effect with longitudinally polarized neutrons

In the scalar Aharonov-Bohm effect, a charged particle (electron) interacts with the scaler electrostatic potential U in the field-foe (i.e., force-fr ee) region inside an electrostatic cylinder (Faraday cage). Using a perfect single-crystal neutron interferometer we have performed a ''dual'' scalar Aharonov-Bohm experiment by subjecting polarized thermal neutrons to a puls ed magnetic field. The pulsed magnetic field was spatially uniform, preclud ing any force on the neutrons. Aligning the direction of the pulsed magneti c field to the neutron magnetic moment also rules out any classical torque acting to change the neutron polarization. The observed phase shift is pure ly quantum mechanical in origin. A detailed description of the experiment, performed at the University of Missouri Research Reactor, and its interpret ation is given in this paper. [S1050-2947(99)02310-0].