Testing the uncertainty principle using (n,γ) photon beams

Photon beams generated from the Fe(n,γ) and Cr(n, γ) reactions using thermal neutrons from a nuclear reactor, were utilized for resonantly exciting nuclear levels in 50Cr, 62Ni and 68Zn. It is shown that the resonance scattering cross section is related to the Doppler broadening of the nuclear level which in turn is proportional to the mean-square linear momenta of the scattering atoms. At low temperatures, approaches the zero-point mean-square momenta occuring in the Uncertainty relation of the form where are the zero-point mean-square vibrational amplitudes of the atoms of the sample. By measuring the scattering intensities from nuclear scatterers at low temperatures it was possible to deduce the value of the zero-point mean square momenta to a few percent accuracy. When these values were then combined with literature values of which in some cases were determined using the Moessbauer effect, the theoretical lower limit of the Uncertainty principle was approached to within few percent. (author)