Consequence of isospin conservation in nucleon-nucleon scattering

Isospin conservation in nucleon-nucleon scattering leads to an extension of the optical theorem to backward angles. The total neutron-proton and proton-proton cross sections are related to the imaginary parts of the neutron-proton amplitudes at backward angles. We suggest to incorporate the above relations in the phase shift analysis, especially above 600 MeV lab energy were dibaryons are suspected to exist. NUCLEAR REACTIONS Nucleon-nucleon scattering, isospin conservation.