Spin observables in neutron‐proton elastic scattering

We describe here two experiments presently running at PSI using the NA2 polarized neutron beam. They are devoted to the measurement of 2‐ and 3‐spin observables in np elastic scattering for kinetic energies from 230 to 590 MeV with a center of mass angular range from 60 to 180 degrees. The goal is to determine the five NN scattering amplitudes for isospin 0 in a model independent way. Preliminary results for KOSKO and KOSSO spin‐transfers are presented.