A three-nucleon problem at high energy : energy dependence of backward p - d elastic scattering below 1 GeV

A review is made of the experimental and theoretical situations concerning the backward elastic scattering of protons by deuterons in the 25-1,500 MeV region. Empirical evidence is shown for a new process beginning at about 300 MeV, which must be added to ordinary nucleon exchange. It appears that experimental data in this energy region can be fitted quite well with a model which employs the isospin 3/2 nucleon resonance at 1,236 MeV in an intermediate state of the three nucleon system. The presence of a N* (I = 1/2) resonance in the ground state of the deuteron is therefore not necessary. The intermediate state model for the three nucleon system involves a three-body force