Relativistic contribution of the final-state interaction to deuteron photodisintegration

The contribution of the final-state interaction to the differential cross section of deuteron photodisintegration at laboratory photon energies below 50 MeV is analyzed in the framework of Bethe-Salpeter formalism with a phenomenological rank-one separable interaction. The approximations made are the neglect of two--body exchange currents, negative-energy components of the bound-state vertex function and the scattering T matrix. It has been found that the gross effect of the final-state interaction with J ≤ 1 comes from the net contributions of the spin-triplet final states and spin-singlet 1S0+ state. The relativistic results are compared with the nonrelativistic ones in every partial-wave channel. It is found that the relativistic effects change the magnitude of the final-state interaction from several percent to several tens of percent