Field-theoretical description of nuclear matter with only the pion-nucleon interaction.

Abstract

A relativistic Lagrangian for the nuclear matter consisting of nucleons and pions with a pseudoscalar interaction term is considered. It is shown that a nonrelativistic reduction of the problem automatically introduces a Lorentz scalar, isoscalar coupling of nucleons with two correlated pions. The corresponding Hamiltonian is used to study the properties of infinite nuclear matter nonperturbatively, treating both the nucleons and pions as quantized fields. The model is shown to reproduce the characteristic nuclear matter properties very nicely without the necessity of {sigma} and {omega} fields, as is usually done in the mean field Walecka model. The corresponding equation of state for zero temperature nuclear matter is calculated and is shown to be consistent with the known phenomenological equations of state. The binding energy of nuclear matter is calculated to be 15.3 MeV at a saturation density of 0.153 fm{sup {minus}3}. The model reproduces a softer nuclear matter with the incompressibility of 134 MeV. {copyright} {ital 1996 The American Physical Society.}