{"paper":{"title":"Photoproduction off the nucleon revisited: Evidence for a narrow N(1688) resonance?","license":"","headline":"","cross_cats":[],"primary_cat":"hep-ex","authors_text":"A. Kim, A. Ni, G. Yang, J. Jang, M. V. Polyakov, T. Boiko, V. Kuznetsov, W. Kim","submitted_at":"2008-01-05T04:28:56Z","abstract_excerpt":"Revised analysis of $\\Sigma$ beam asymmetry for the $\\eta$ photoproduction on the free proton reveals a structure at $W\\sim 1.69$ GeV. Fit of the experimental data based on the E429 solution of the SAID partial wave analysis suggests a narrow ($\\Gamma \\leq 25$ MeV) resonance. Possible candidates are $P_{11}, P_{13}$, or $D_{13}$ resonances. The result is considered in conjunction 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."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0801.0778","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}