Unified description ofπd-πd,πd-NN, and NN-NN reactions at intermediate energies

The theory of the coupled πNN-NN systems is applied to the unified description of the πd-πd, πd-NN, and NN-NN reactions in the intermediate energy range. Off-shell modifications are introduced in the $P_{33}$ and $P_{11}$ πN channels and the effects of heavy meson exchange are investigated. In general, results for various observables are in agreement with experiments. We have assessed certain aspects upon which future work should improve.