Model dependence of unitary isobar model treatments of NN-->NN pi at intermediate energies.

Abstract

We compare two ``conventional'' relativistic unitary isobar models for the NN\ensuremath{\rightarrow}NN\ensuremath{\pi} reaction. One model, which preserves two- and three-body unitarity, contains only pion exchange, while the other, based on a two-body coupled-channels approach, includes heavier meson exchanges. Thus, we attempt to identify the model dependence of predictions for the NN\ensuremath{\rightarrow}NN\ensuremath{\pi} process over a large part of final state phase space. Differential cross sections and a variety of spin observables are examined. Implications for the identification of exotic dibaryon resonances are briefly discussed.