NN phase shift analysis, K‐matrix, and optimal polynomial theory

In this paper we discuss a new phase shift analysis and give some results for pp and np scattering. An improvement over the standard method of phase shift analysis is presented by the inclusion of the cut for 4mπ?t≲45mπ2. Unitarization is achieved through application of a K‐matrix formalism where we employ for the first time in NN, the ’’derivative amplitudes’’. We compare the theoretical predictions for the peripheral waves with the trends predicted by a new version of Optimal Polynomial Theory (OPT). With the analysis described here we aim at better determination of non‐peripheral phase shifts and a smooth transition between peripheral and non‐peripheral phases.