The effect of the Δ(1236) on the imaginary component of nucleon-nucleon phase shifts

A study is made, within the Δ-configuration approach, of several processes, which could contribute to the imaginary components of nucleon-nucleon phase shifts. However, as in our earlier estimates with this model, the final results for low partial waves are far from the values suggested by phase shift analyses. The imaginary components in high partial waves are calculated in Born approximation and could be utilized in removing some of the ambiguities in phase shift analyses at energies less than 1 GeV. In addition a new transition potential for generating Δ-configurations is derived in such a way as to be more consistent with two-pion exchange contribution of recent semitheoretical nucleon-nucleon potentials. (author)