CALCULATION OF THE INELASTIC-LIGHT-SCATTERING SPECTRUM IN HE-4 IN THE2-BODY APPROXIMATION

We describe calculations of the inelastic-light-scattering spectrum fo r frequencies of the order of up to several times the roton frequency. The calculations are based on the two-body approximation in a theoret ical description of the fluid due to Manousakis and Pandharipande. On the basis of earlier results we calculate only the contribution arisin g from quasiparticle anharmonicities in the spectrum and take full acc ount of the strong dependence of the three-quasiparticle coupling on t he magnitudes and directions of the momenta of the quasiparticles, whi ch is implied by the two-body approximation. The results are compared with recent experimental results. At high energies, the calculated spe ctrum is in most respects consistent with the experimental one. We dis cuss the possible origins of the remaining discrepancies.