Scattering from the two-roton, two-maxon and maxon-roton spectrum in superfluid4He

✍ Scribed by A. Griffin; K.J. Juge

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 133 KB
• Volume: 194-196
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(94)90580-0

✦ Synopsis

Stimulated by recent high-resolution neutron data from ILL, we have carried out an extensive numerical study of the single-particle pa (Q, w) and the two-particle p2 (Q, w) spectral densities within the well known Ruvalds and Zawadowsld (ZS) scenario, over a wide range of wavevectors (1 < Q < 3~-1), frequencies and temperatures. We extend the original RZ analysis (which concentrated on the two-roton spectrum) to include the mulitparticle structure associated with the maxon-roton and maxon-maxon spectra. The microscopic theory of a Bose-condensed fluid shows that S(Q, w) involves a weighted sum of pl(Q, w) and p2(Q, ~). As a result, multiparticle structure exhibited by S(Q, w) is not easily related to theoretical results for p~(Q, w) and p2(Q, w).