Density dependence of the momentum distribution in normal liquidHe4

Abstract

Deep inelastic neutron scattering measurements on normal liquid ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ at 4.25 K have been carried out at 11 densities between 0.125 (saturated vapor pressure) and 0.200 g/${\mathrm{cm}}^3$, at a momentum transfer of 23 A${̊}^{\mathrm{-}1}$. A sum of two Gaussians is required to characterize the scattering at all densities, even when the broadening due to instrumental resolution and corrections to the impulse approximation are included. The kinetic energy varies from 15.5 K at 0.125 g/${\mathrm{cm}}^3$ to 32.7 K at 0.200 g/${\mathrm{cm}}^3$.