A Few Simple Observations on Pion-Condensation in Nuclei

Abstract

We present a few simple observations on the occurrence of $\pi$-condensation in Nuclei, aimed at clarifying the nature of the $\pi$-condensation implied by the coherent nuclear $\pi$-N-$\Delta$ interaction, proposed in 1990 to explain the puzzling emergence of the Shell-Model. We show that such condensation is totally unrelated to the one proposed by A. B. Migdal at the beginning of '70, which can easily be shown not to occur at the normal nucleon density $\rho_{N}\simeq$ 0.17 fm${}^{-3}$.