Relativistic complex separable potential of the neutron-proton system

Within a covariant Bethe-Salpeter approach, a relativistic complex separable kernel for the description of the neutron-proton interaction, is proposed. The uncoupled partial-wave states with total angular momentum J=0,1 are considered. The multirank separable potentials elaborated earlier are real-valued and, therefore, make it possible to describe only the elastic part (phase shifts, low-energy parameters, etc.) of the neutron-proton scattering. The description of the inelasticity comes out of an imaginary part introduced into these potentials. To obtain this part the experimental data for the inelasticity parameter up to the laboratory energy 3 GeV are used. A signal of wide dibaryon resonances in the P0+3 partial-wave state is discussed.