Point-coupling Models from Mesonic Hypermassive Limit and Mean-field Approaches

Abstract

In this work, we show how nonlinear point-coupling models, described by a Lagrangian density containing only terms up to fourth order in the fermion condensate \((\bar{\psi}\psi)\), are derived from a modified meson-exchange nonlinear Walecka model. We present two methods of derivation, namely the hypermassive meson limit within a functional integral approach and the mean-field approximation, in which equations of state at zero temperature of the nonlinear point-coupling models are directly obtained.