Showing papers by "J. Mayers published in 1996"

Model-independent analysis of inelastic-neutron-scattering data at high momentum transfer

Abstract: A model-independent procedure is proposed which allows us to obtain the asymptotic scaling function at infinite momentum transfer and a comprehensive assessment of deviations of deep inelastic-neutron-scattering data from a perfect scaling behavior, which are due to the finite values of energy and momentum transfers to the target atom. The procedure is applied to simulated and experimental data on polycrystalline ZrH{sub 2} at {ital T}=20 and 290 K. We observe that the impulse approximation, valid for infinite energy and momentum transfers, is not yet completely reached at the finite momentum transfer values {ital q} of neutron experiments even at {ital q}{approx_equal}60 {ital A}{sup {minus}1}. It is argued that, beyond the specific case of ZrH{sub 2}, this procedure can be used for the description of deep inelastic-neutron scattering from other molecular and atomic systems. {copyright} {ital 1996 The American Physical Society.}

Density evolution of the atomic momentum distribution in liquid and solid hydrogen

Abstract: The density evolution of the atomic momentum distribution has been measured in liquid and solid hydrogen at constant temperature T = 20.4K and in the pressure range between 0 and 1180 bar. The experiment was carried out on the eVS spectrometer, at the pulsed neutron source ISIS, where the energy range of the available neutrons allows one to look directly at the proton wave function. The resulting kinetic energy of the protons is checked against other experimental results where the kinetic energy of centers of mass was measured.

Anomalous neutron and Raman scattering due to EPR correlated protons in liquid water

Abstract: The quantum interference of resonant states may lead to novel short-lived and spatially restricted Einstein-Podolsky-Rosen correlations between particles in condensed matter. This is predicted to cause the appearance of certain “anomalous” intensity components in scattering experiments. Very recently, this effect was measured in (i) Raman light scattering and (ii) deep inelastic neutron scattering from H2O-D2O mixtures at room temperature. Current results of these two experiments are reported and compared.