Coupled-channel potential for nucleons and deltas

We propose a nucleon-nucleon potential for which the NN, NΔ, and ΔΔ channels are coupled by energy-independent, nonlocal interactions constructed from meson-exchange interactions. The same vertex couplings that were utilized in earlier studies based on the Bonn single-channel NN potential are adopted. We arrive at our interaction by applying an extension of the folded diagram expansion to coupled channels. The coupled-channel formalism facilitates studies of the interplay between nucleon and delta degrees of freedom and bound-state properties of nuclear matter and finite nuclei. It also establishes a framework that might simplify the treatment of nucleon-nucleon scattering to energies above pion-production threshold.