Evidence for a narrow structure at W~1.68 GeV in eta photoproduction on the neutron


Abstract in English

New results on quasi-free $eta$ photoproduction on the neutron and proton bound in a deuteron target are presented. The $gamma n to eta n$ quasi-free cross section reveals a bump-like structure which is not seen in the cross section on the proton. This structure may signal the existence of a relatively narrow ($Msim 1.68$ GeV, $Gamma leq 30$ MeV) baryon state.

Download