On the Raman Scattering in Liquid Helium

Publisher Website
Google Scholar
Abstract
General treatment is given on the final state interaction between a pair of elementary excitations produced by the Raman scattering on liquid helium. The final state interaction exerts a drastic influence on the Raman spectrum where the produced excitations have small group velocities, i.e. the excitations lie near the extremum points of the phonon-roton dispersion curve. It is shown that, in general, the Raman spectrum has no peaks at these points in spite of the infinite density of states, and correct form of the spectrum is given. The result is interpreted as a destructive interference between excitations with positive and with negative group velocities. Possible existence of a resonance, which depends on the sign of the interaction between the excitations around the extrema, is also investigated.

This publication has 0 references indexed in Scilit: