{"paper":{"title":"Low-energy $\\eta$-nucleon interaction studied with $\\eta$ photoproduction off the deuteron","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["hep-ex","hep-ph","nucl-ex"],"primary_cat":"nucl-th","authors_text":"2), (2) Univ. Cruzeiro do Sul, (3) KEK, 4), (4) J-PARC, (5) ELPH, 6) ((1) Osaka Univ., (6) Tohoku Univ.), H. Kamano (3, S. X. Nakamura (1, T. Ishikawa (5","submitted_at":"2017-04-24T03:39:10Z","abstract_excerpt":"We develop a reaction model for $\\eta$ photoproduction off the deuteron ($\\gamma d\\to\\eta pn$), and study the reaction at a special kinematics, where the photon beam energy is $\\sim 0.94$ GeV and the scattered proton is detected at $\\sim 0^\\circ$, for the purpose of determining the $\\eta$-nucleon scattering length ($a_{\\eta N}$) and effective range ($r_{\\eta N}$). In this kinematics, the $\\eta$-nucleon elastic rescattering is significantly enhanced while other background mechanisms being suppressed. We show that a ratio $R$, the $\\gamma d\\to\\eta pn$ cross section divided by the $\\gamma p\\to\\et"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1704.07029","kind":"arxiv","version":2},"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"}