INFLUENCE OF N-DELTA AND DELTA,DELTA CHANNELS ON THE SATURATION PROPERTIES OF NUCLEAR-MATTER

The nuclear matter properties are studied in the framework of the Bethe-Brueckner-Goldstone theory including explicitly the Δ-isobar degrees of freedom through a full coupled channel calculation of the two-body reaction matrix. This is accomplished using a separable representation of the Argonne v28 potential. Two possible choices of the single-nucleon potential, the standard "gap choice" and the "continuous" choice, are studied and compared. The relevance of the potential felt by the Δ inside the nuclear medium is pointed out. It is found that for a correct description of the nuclear matter properties the explicit treatment of the Δ is essential. © 1990.