DERIVING THE QUARK CONDENSATE WITHIN A FINITE FERMI SYSTEM FROM THE GENERATING FUNCTIONAL OF CHIRAL PERTURBATION-THEORY

The generating functional of heavy-baryon chiral perturbation theory a t order O(Q(2)) in the mean field approximation (with a pseudoscalar s ource coupling which is consistent with the PCAC-Ward identities on th e current quark level) has been exploited to derive Migdal's in-medium pion propagator. It is shown that the prediction for the density depe ndence of the quark condensate obtained on the composite hadron level by embedding PCAC within the framework of Migdal's approach to finite Fermi systems is identical to that resulting from QCD.