| Abstract: | The normal liquid helium 3 one-body momentum distribution, n(k),
at zero and finite temperature is evaluated by using the cluster
expansion theory for the occupation probability of Ristig-Clark
formalism. The lowest order constrained variational (LOCV) and the
extended LOCV (ELOCV) method are used to calculate the correlation
functions at zero and finite temperatures. The input inter-atomic
potential is the familiar 6–12 Lennard-Jones interaction. The gap in
n(k) at the Fermi surface is found to be about 0.41 comparing to
1.0 (0.72) for the noninteracting (dilute hard-sphere) Fermi gas
model at zero temperature and it decreases by increasing the
temperature. It is also demonstrated that the high-momentum tail of
n(k) gets larger as we increase the temperature and finally, we
find a good agreement between present calculated n(k) and those
coming from more sophisticated approaches such as Diffusion and
Green-function Monte Carlo techniques. |
