Relativistic multirank interaction kernels of the neutron–proton system

The multirank separable kernels of the neutron–proton interaction for uncoupled S and P partial waves (with the total angular momentum J=0,1) are proposed. Two different methods of a relativistic generalization of initially nonrelativistic form factors parametrizing the kernel are considered. Using the constructed kernels the experimental data for phase shifts in the elastic neutron–proton scattering for the laboratory energy up to 3 GeV and low-energy parameters are described. The comparison of our results with other model calculations are presented.