Partial-wave analysis of nucleon-nucleon scattering below the pion-production threshold

Abstract

We undertake a simultaneous partial wave analysis of proton-proton and neutron-proton scattering data below the pion production threshold up to laboratory energies of $350\phantom{\rule{4.pt}{0ex}}\text{MeV}$. We represent the interaction as a sum of $\ensuremath{\delta}$ shells in configuration space below $3\phantom{\rule{4.pt}{0ex}}\text{fm}$ and a charge dependent one pion exchange potential above $3\phantom{\rule{4.pt}{0ex}}\text{fm}$ together with electromagnetic effects. We obtain a chi square value of 2813, for pp, and 3985, for nn, with a total of 2747 and 3691 pp and nn data, respectively, obtained till 2013 and a total number of 46 fitting parameters yielding a chi square value by degree of freedom of ${\ensuremath{\chi}}^{2}/\mathrm{d}.\mathrm{o}.\mathrm{f}=1.06$. Special attention is payed to estimate the errors of the phenomenological interaction as well as the derived effects on the phase shifts and scattering amplitudes.