We examine the effects of pseudoscalar and pseudovector coupling of the $\pi$ and $\eta$ mesons in one-boson exchange models of the $\mathrm{NN}$ interaction using two approaches: time-ordered perturbation theory unitarized with the relativistic Lippmann-Schwinger equation, and a reduced Bethe-Salpeter approach using the Thompson equation. Contact terms in the one-boson exchange amplitudes in time-ordered perturbation theory lead naturally to the introduction of s-channel nucleonic cutoffs for the interaction, which strongly suppresses the far off-shell behavior of the amplitudes in both approaches. Differences between the resulting $\mathrm{NN}$ predictions of the various models are found to be small, and particularly so when coupling constants of the other mesons are readjusted within reasonable limits.

• Received 3 May 2002

DOI:https://doi.org/10.1103/PhysRevC.66.044006