FERMI-LIQUID PARAMETERS OF HE3 IN BRUECKNER THEORY

Functional differentiation of the Brueckner-theory equations gives a prescription for calculating the effective interaction in a Fermi liquid. The many terms that result from the differentiation are calculated for the liquid-He3 system using Østgaard's reaction matrices. He3 is strongly interacting in the sense that the defect wave-function probability κ is large, of the order 0.56. As a result, many of the terms contribute substantially to the total. Of the Landau parameters f0, f1, and z0, only z0 is in reasonable agreement with experiment. The parameter f0 is too small. This is known to be due in part to the neglect of three-body clusters. We find a small value for f1, implying that the effective mass m* is close to one. Larger effective masses could be obtained by treating low-momentum-transfer processes more carefully and by summing higher-order diagrams. © 1969 The American Physical Society.