πNN system with two-term potentials in the P33 and P11 πN channels

The πNN system is studied with two-term potentials for the πN interaction in the P33 and P11 channels. Such model systematics as the difference in the dominant πN P33 input, the effect of the so-called backward propagating pion, the choice of the relative momenta (magic vectors) at the isobar vertices, etc., are investigated. The results in the πd-πd, πd-NN, and NN-NN reactions at intermediate energies are compared with the available experimental data. The overall quality of the predictions by the present approach is roughly comparable to that based upon the one-term P33 isobar model supplemented by an appropriate ad hoc off-shell modification, but with a significant improvement in the description of the πd-NN asymmetry Ay0