the remainder of this paper we will ignore such effects.

Let us now suppose that we had a detailed microscopic model of the $\omega$ meson which enables us to calculate a momentum dependent $\omega$ self energy, $\pi_{\omega}(q^2)$. As a matter of convention, we will include any effects of mass and wavefunction renormalizations of the $\omega$ in $\pi_{\omega}(q^2)$. This means that $\pi_{\omega}$ and its derivative vanishes at $q^2=m_\omega^2$. The omega exchange part of the N-N potential with such a model is given by $$V_{\omega}(q^2) = \frac{( \hat{g}_{\omega}^{\rm
v}(q^2)\gamma^{(1)}_{\mu} \, +  \, \hat{g}_{\omega}^{\rm t}(q^2)
q^\alpha \sigma^{(1)}_{\alpha \mu}  ) (g^{\mu \nu} -
q^{\mu}q^{\nu}/m_{\omega}^2) (\hat{g}_{\omega}^{\rm v}(q^2)
\gamma^{(2)}_{\nu} + \hat{g}_{\omega}^{\rm t}(q^2) \sigma_{\nu
\beta}
q^\beta )  }{q^2 - m_\omega^2 + \pi_\omega(q^2)}\;.
\label{oep2}$$ We have written the couplings as $\hat{g}_{\omega}^{\rm v,t}$ and rather than $g_{\omega}^{\rm v,t}$ to make evident the fact that the vertex functions used in the model in eq. (\[oep2\]) need not be the same as the vertex functions used in the model in eq. (\[oep\]): [*these vertex functions are phenomenological and depend on how the rest of the problem is treated*]{}.

Given that the vertex functions may differ between the two models, we note that the two models may be identical—[*i.e.*]{} they may be 