ASYMPTOTIC-BEHAVIOR OF THE SCALING FUNCTION IN DEEP INELASTIC NEUTRON-SCATTERING

A new method is proposed to obtain the atomic momentum distribution from deep inelastic neutron scattering in the framework of y scaling. The analysis is based on a model independent extrapolation to obtain the asymptotic scaling function at infinite momentum transfer (q --> infinity) from the experimental cross sections at finite momentum transfer, even if the data are affected by final state interactions. This method is an extension of an approach to y scaling already adopted to obtain the nuclear momentum distribution in nuclei. An application to polycrystalline D2O at 20 K shows that the momentum distribution of deuterium obtained with the asymptotic scaling function strongly differs from the results corresponding to the scaling function at finite momentum transfer.