Theory of deep inelastic neutron scattering. II. Application to normal and superfluid /sup 4/He

Journal Article · Wed Mar 01 04:00:00 EST 1989 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.39.4022· OSTI ID:6342870

Silver, R N

The hard-core perturbation theory (HCPT) predictions for high-momentum-transfer neutron scattering from liquid /sup 4/He are numerically evaluated. The input to the calculations are Monte Carlo and variational momentum distributions, the radial distribution function, and the Jeffreys-Wentzel-Kramers-Brillouin phase shifts for the He potential. Consistent with the ..omega../sup 2/ sum rule, the Gaussian width of the dynamic structure function S(Q,..omega..) is the same in HCPT and in the impulse approximation (IA). However, where the IA predicts structure in S(Q,..omega..) below T/sub lambda/ due to the Bose condensate, HCPT predicts that S(Q,..omega..) is smoothed by final-state broadening. The final-state effects are negligible for the normal fluid above T/sub lambda/. The approach to the IA at high Q is shown to be O(logQ) for the He-He potential, which implies that S(Q,..omega..) satisfies approximate Y scaling and that final-state broadening is significant for all feasible experiments. Extensions of HCPT to lower Q and to other systems are qualitatively discussed. The problem of extracting momentum distributions in quantum fluids and solids from high-Q neutron scattering is addressed.

• Research Organization: Theoretical Division, Los Alamos Neutron Scattering Center, MS B262, Group T-11, Los Alamos National Laboratory, Los Alamos, New Mexico 87545
• OSTI ID: 6342870
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 39:7; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

640450* -- Fluid Physics-- Superfluidity
654003 -- Radiation & Shielding Physics-- Neutron Interactions with Matter
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
DEEP INELASTIC SCATTERING
EVEN-EVEN NUCLEI
FLUIDS
HELIUM 4
HELIUM II
HELIUM ISOTOPES
IMPULSE APPROXIMATION
INELASTIC SCATTERING
INTERACTIONS
ISOTOPES
LEPTON-BARYON INTERACTIONS
LEPTON-HADRON INTERACTIONS
LEPTON-NUCLEON INTERACTIONS
LIGHT NUCLEI
LINEAR MOMENTUM TRANSFER
MOMENTUM TRANSFER
NEUTRAL-PARTICLE TRANSPORT
NEUTRON TRANSPORT
NUCLEI
PARTICLE INTERACTIONS
QUANTUM FLUIDS
RADIATION TRANSPORT
SCATTERING
STABLE ISOTOPES