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

We investigate the relationship between the rank-1 separable potential for the covariant Bethe-Salpeter equation and the one-boson-exchange potential. After several trials using different the parameter choices, we found that it is not always possible to reproduce the phase-shifts calculated from a single term of the one-boson-exchange potential, in particular from the σ-exchange term, separately using the rank-1 separable potential. Instead, it is shown that the separable potential is useful to parametrize the total nucleon-nucleon interaction.