Pion Condensation Based on Relativistic Formulation

The critical density of neutral pion condensation is investigated based on the relativistic framework and compared with nonrelativistic results. The particle-hole and delta-hole polarizations of the pion selfenergy are calculated in the relativistic way by using a new set of Landau-Migdal parameters derived from a recent experimental data.

It is concluded that the use of relativistic particle-hole and delta-hole excitations for the pion selfenergy increases the critical density compared with the non-relativistic result, however still leads to condensation for densities from 2 to 4 times normal nuclear matter density.