Fermi pairing in dilute 3He-HeII mixtueres

In this paper the Galitskii-Migdal-Feynman (GMF) formalism is applied to dilute He-3-HeII mixtures. In particular, the effect of the hole-hole scattering on pairing in these systems is investigated. To this end, the relative phase shifts incorporating many-body effects based on both Brueckner-Bethe-Goldstone (BBG) and GMF formalisms axe calculated. In the GMF formalism, the S-wave phase shift at zero relative momentum is -pi and has a cusp at the Fermi momentum; while in the BBG formalism, this phase shift has zero values up to the Fermi momentum. From these results we conclude that hole-hole scattering plays a crucial role in any possible fermion-fermion pairing in these systems.