Nucleon resonances and the production of light vector mesons near   thresholds
  The production of the light vector mesons $V = \rho, \omega, \phi$ in the reactions $\pi N \to V N$ and $N N \to V N N$ near threshold is studied. The subsequent electromagnetic decay $V \to \gamma^* \to e^+ e^-$ is particularly suited for exploring subthreshold $\omega N$ resonances. 
B. Kampfer, L.P. Kaptari, A.I. Titov