Relation between the separable and one-boson-exchange potential for the covariant Bethe-Salpeter equation

We investigate the relation between the rank I separable potential for the covariant Bethe-Salpeter equation and the one-boson-exchange potential. Parameters of the two potentials are related in the long wave length limit. It turns out that it is difficult to reproduce the phase-shifts calculated from a single term of the one-boson-exchange potential, separately by the rank I separable potential. Instead, it is shown that the separable potential is useful to parameterize the total nucleon-nucleon interaction