On the Coupling of the $\eta $ Meson to the Nucleon
  The pseudoscalar and pseudovector $\eta N$ coupling constants are calculated from an effective vertex associated with the $a_0(980)\pi N$ triangle diagram. The predicted values are in agreement with the ones concluded from fitting $\eta $ photoproduction amplitudes. In this context we stress the importance of the properties of the scalar meson octet for $\eta $ meson physics. 
M. Kirchbach, L. Tiator