We show that the assumption of dropping meson masses together with conventional many-body effects, implemented in the relativistic Dirac-Brueckner formalism, explains nuclear saturation. We use a microscopic model for correlated $2\pi$ exchange and include the standard many-body effects on the in-medium pion propagation, which initially increase the attractive nucleon-nucleon ( $\mathrm{NN}$) potential with density. For the vector meson exchanges in both the $\pi \pi$ and $\mathrm{NN}$ sector, we assume Brown-Rho scaling which—in concert with “chiral” $\pi \pi$ contact interactions—reduces the attraction at higher densities.

• Received 3 June 1997

DOI:https://doi.org/10.1103/PhysRevLett.82.1827