Quantitative study of the Zawadowski-Ruvalds-Solana model of the dynamics of liquid helium

R. Hastings, J W Halley

Research output: Contribution to journalArticle

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Abstract

We study the Zawadowski-Ruvalds-Solana (ZRS) model of quasiparticle interactions in liquid helium both quantitatively and theoretically. We find that the model cannot account quantitatively for the multiphonon peak in the neutron-scattering spectrum even if we vary the quasiparticle spectrum phenomenologically. We find that the model can account for the experimental light-scattering spectrum if the effective roton-roton coupling g4(k,k) is sharply peaked at the roton minimum (kkk0). We suggest that the neutron-scattering results would be improved without changing the light-scattering prediction if the density operator contained nonlinear terms in the quasiparticle operator. We criticize the implicit assumption in the ZRS model that the zero-order ground state is nondegenerate. The relationship of this model to one devised by Jackson is discussed.

Original languageEnglish (US)
Pages (from-to)2488-2500
Number of pages13
JournalPhysical Review A
Volume10
Issue number6
DOIs
StatePublished - Jan 1 1974

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liquid helium
rotons
neutron scattering
light scattering
operators
ground state
predictions
interactions

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Quantitative study of the Zawadowski-Ruvalds-Solana model of the dynamics of liquid helium. / Hastings, R.; Halley, J W.

In: Physical Review A, Vol. 10, No. 6, 01.01.1974, p. 2488-2500.

Research output: Contribution to journalArticle

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