Backward-angle η photoproduction from protons at Eγ=1.6-2.4

Abstract

Differential cross sections for η photoproduction from protons have been measured at Eγ=1.6-2.4 GeV in the backward direction. A bump structure has been observed above 2.0 GeV in the total energy. No such bump is observed in η',ω, and π0 photoproductions. It is inferred that this unique structure in η photoproduction is due to a baryon resonance with a large ss̄ component that is strongly coupled to the ηN channel. © 2009 The American Physical Society.