# Photoproduction off the nucleon revisited: Evidence for a narrow N1688 resonance - High Energy Physics - Experiment

Abstract: Revised analysis of $\Sigma$ beam asymmetry for the $\eta$ photoproduction onthe free proton reveals a structure at $W\sim 1.69$ GeV. Fit of theexperimental data based on the E429 solution of the SAID partial wave analysissuggests a narrow $\Gamma \leq 25$ MeV resonance. Possible candidates are$P {11}, P {13}$, or $D {13}$ resonances. The result is considered inconjunction with the recent evidence for a bump-like structure at $W\sim 1.67 -1.68$ GeV in the quasi-free $\eta$ photoproduction on the neutron.

Author: V. Kuznetsov, M. V. Polyakov, T. Boiko, J. Jang, A. Kim, W. Kim, A. Ni, G. Yang

Source: https://arxiv.org/