No abstract

It is found that the optimal determinantal approximation, as proposed in an earlier paper, leads to accurate solutions for the ND~l equations of irN scattering in the P n state. Both left-hand and right-hand cutoff procedures are used in the formulation of the problem, with similar results. Inelasticity is treated by a method proposed by Froissart. It is shown that a qualitatively correct irN P n phase shift in the low-energy region may be reproduced in a one-channel calculation without Castillejo-Dalitz-Dyson poles, provided that the inelasticity factor is chosen properly. A two-channel model with the (wN*) as the second channel is discussed, and it is shown that the inelasticity obtained in a rough approximation to the coupled unitarity relations is adequate in generating the "zero" of the Pu phase shift. Some implications concerning the nonequivalence of one-channel and multichannel ND~X formalisms are discussed.