PI-NN SYSTEM WITH 2-TERM POTENTIALS IN THE P-33 AND P-11 PI-N CHANNELS

The pi-NN system is studied with two-term potentials for the pi-N interaction in the P-33 and P11 channels. Such model systematics as the difference in the dominant pi-N P-33 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 pi-d-pi-d, pi-d-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 P-33 isobar model supplemented by an appropriate ad hoc off-shell modification, but with a significant improvement in the description of the pi-d-NN asymmetry A(y0).