LOW-ENERGY AND INTERMEDIATE-ENERGY NUCLEON-NUCLEON INTERACTIONS AND THE ANALYSIS OF DEUTERON PHOTODISINTEGRATION WITHIN THE DISPERSION-RELATION TECHNIQUE

Nucleon-nucleon interactions in the region of the nucleon kinetic ener gies up to 1000 MeV are analysed together with the reaction gamma d -- > pn in the photon energy range up to E-gamma = 400 MeV. The following nucleon-nucleon s-channel partial amplitudes are reconstructed in the dispersion relation N/D method: S-1(0), S-3(1) -D-3(1), P-3(0), P-1(1 ), P-3(1), P-3(2), D-1(2), D-3(2) and F-3(3). Correspondingly, the dis persive representation of partial amplitudes N Delta --> pn, NN --> p n and NN pi --> pn is given and parameters which determine these two b aryon amplitudes are found. Basing on that, we ha je performed paramet er-free calculation of the amplitude gamma d --> pn, taking into accou nt: (i) pole diagram, (ii) nucleon-nucleon final-state rescattering ga mma d --> pn --> pn, and (iii) inelastic final-state rescatterings gam ma d --> N Delta(1232) --> pn, gamma d --> NN(1400) --> pn and gamma d --> NN pi --> pn. The gamma d --> pn partial amplitudes for the abov e-mentioned channels are found. It is shown that the process gamma d - -> pn --> pn is significant for the waves S-1(0), P-3(0), P-3(1), at E -gamma = 50 - 100 MeV, while gamma d --> N Delta --> pn dominates for the waves P-3(2), D-1(2), F-3(3) at E-gamma > 300 MeV. Meson exchange current contributions into the deuteron disintegration are estimated: they are significant at E-gamma = 100 - 400 MeV.