A case for a narrow nucleon excitation N*(1685)
Maxim Polyakov (Bochum)

I will discuss various evidencies for a narrow nucleon resonance. In particular, the first study of quasi-free Compton scattering on the neutron in the energy range of \(E_{\gamma}=0.75 - 1.5\) GeV is presented. The data reveals a narrow peak at \(W\sim 1.685\) GeV. This result, being considered in conjunction with the recent evidence for a narrow structure at \(W\sim 1.68\)GeV in the \(\eta\) photoproduction on the neutron, suggests the existence of a new nucleon resonance with unusual properties: the mass \(M\sim 1.685\)GeV, the narrow width \(\Gamma \leq 30\)MeV, and the much stronger photoexcitation on the neutron than on the proton.