MEASUREMENT-THEORETICAL ANALYSIS OF NEUTRON INTERFERENCE AT LOW TRANSMISSION PROBABILITY

Recent experimental results of neutron interferometry at low transmission probability are analyzed when an absorber is present in one of the two routes of the interferometer. The process is regarded as a partial dephasing characterized by the decoherence parameter, along the same line of thought as in the many-Hilbert-space approach to the quantum measurement problem. It is shown that the density fluctuations of the elementary constituents of the absorber provoke a reduction of the visibility of the interference pattern. The effect is evaluated analytically in the case of Gaussian fluctuations, and found to be in agreement with the experimental data