On the relevance of Δ-Δ andN-Δ correlations in nuclear matter calculations

Summary

The relevance of short range correlations between two Δ's or a Δ and a nucleon in evaluating the nuclear binding energy is shown, first by means of a naive model and then within a coupled-channel calculation in which the Hilbert space is enlarged in order to include the Δ resonance as well. It comes out that direct ω-exchange between Δ’s or a Δ and a nucleon gives rise, as expected, to a significant repulsion, but the π-and ρ-exchange in the same conditions can provide, with reasonable parameters, an extra binding whose relevance has not been exhaustively explored yet.