Simple microscopic model for the scalar-isoscalar component of the Landau-Migdal amplitude

A simple microscopic model is proposed that describes the coordinate depend ence of the zeroth harmonic f(0)(r) of the scalar-isoscalar component of th e Landau-Migdal amplitude. In the theory of finite Fermi systems due to Mig dal, such a dependence was introduced phenomenologically. The model present ed in this study is based on a previous analysis of the Brueckner G matrix for a planar slab of nuclear matter; it expresses the function f(0)(r) in t erms of the off-mass-shell T matrix for free nucleon-nucleon scattering. Th e result involves the T matrix taken at the negative energy value equal to the doubled chemical potential mu of the nucleus being considered. The ampl itude f(0)(r) found in this way is substituted into the condition that, in the theory of finite Fermi systems, ensures consistency of the self-energy operator, effective quasiparticle interaction, and the density distribution . The calculated isoscalar component of the mean nuclear field V(r) agrees fairly well with a phenomenological nuclear potential. Owing to a strong E dependence of the T matrix at low energies, the potential-well depth V(0) d epends sharply on mu, increasing as \mu\ is reduced. This effect must addit ionally stabilize nuclei near the nucleon drip line, where mu vanishes. (C) 2001 MAIK "Nauka/Interperiodica".