Density matrix and momentum distribution of helium liquids and nuclear matter

Journal Article · Fri Jul 01 04:00:00 EDT 1977 · Phys. Rev., B; (United States)

DOI:https://doi.org/10.1103/PhysRevB.16.222· OSTI ID:7142264

Lam, P M; Clark, J W; Ristig, M L

The one-body density matrix n(r) and the associated momentum distribution n(k) (for given spin-isospin projection) are calculated for the ground states of liquid /sup 4/He, liquid /sup 3/He, and a simple model of nuclear matter, based on suitable Jastrow wave functions PSI = PI/sub i < j/ f (r/sub ij/) PHI. The model function PHI is taken as the ground-state wave function of a system of noninteracting bosons or fermions, as appropriate. The evaluations are performed within the framework of the diagrammatic formalism developed recently by Ristig and Clark. For the most part, the correlations incorporated via the two-body factor f (r) are assumed to be of short range. In the case of /sup 4/He, the asymptotic value rho/sup -1/n(r ..-->.. infinity), which may be identified with the condensate fraction, is found to be 0.119 at the experimental equilibrium value of the particle density rho. In the cases of /sup 3/He and nuclear matter, there is no long-range order, i.e., n (r ..-->.. infinity) = 0. On the other hand, for these Fermi systems the momentum distribution n (k) exhibits a discontinuity z/sub k/F at the Fermi wave number k/sub F/, which measures the strength of the quasiparticle pole. The calculation yields z/sub k/F = 0.350 for liquid /sup 3/He and z/sub k/F = 0.747 for nuclear matter, at the respective equilibrium densities. The results presented for the helium liquids are of considerable interest in connection with proposed scattering experiments using intense neutron beams.

• Research Organization: Department of Physics, Washington University, St. Louis, Missouri 63130
• OSTI ID: 7142264
• Journal Information: Phys. Rev., B; (United States), Journal Name: Phys. Rev., B; (United States) Vol. 16:1; ISSN PLRBA
• Country of Publication: United States
• Language: English

Related Subjects

640460* -- Fluid Physics-- Other Quantum Fluids
653002 -- Nuclear Theory-- Nuclear Matter
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BOSONS
COHERENT SCATTERING
DENSITY MATRIX
DIFFRACTION
ENERGY LEVELS
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
FERMIONS
FUNCTIONS
GROUND STATES
HELIUM 3
HELIUM 4
HELIUM ISOTOPES
ISOTOPES
JASTROW THEORY
LIGHT NUCLEI
LINEAR MOMENTUM
MATRICES
MATTER
NEUTRON DIFFRACTION
NUCLEAR MATTER
NUCLEI
SCATTERING
STABLE ISOTOPES
WAVE FUNCTIONS