Momentum distribution and one-body density matrix in liquidHe.

The momentum distribution n(k) and the one-body density matrix ρ( r, r' have been calculated in normal liquidHe at T=0. A variational wave function containing two-, three-body and backflow correlations has been used. The Fermi hypernetted chain technique has been employed and the elementary diagrams have been evaluated by the scaling approximation. The present estimate of n(k) is in good agreement with the Monte Carlo data obtained with similar wave functions. n(k) and the discontinuity Z of n(k) at the Fermi surface have been computed at several values of the density. The density dependence of the effective mass m has been found to be mainly due to that of Z. [ABSTRACT FROM AUTHOR]