MICROSCOPIC CALCULATION OF THE TEMPERATURE ANOMALY OF SPATIAL CORRELATIONS IN LIQUID-HE-4

We re-investigate G V Chester's model for liquid He-4 which combines Jastrow factor correlations with those of the ideal Bose gas. For the first time, we evaluate the structure factor S(k; T) in this model. This evaluation is based on the optimized random phase approximation frequently used in simple liquid theories. The calculated S(k; T) reproduces qualitatively the k- and T-dependence of the experimental structure factor. The temperature anomaly of liquid helium below the lambda-point can be explained by the Bose gas correlations.