{"paper":{"title":"Meson exchange effects in elastic $ep$ scattering at loop level and the electromagnetic form factors of the proton","license":"http://creativecommons.org/licenses/by/3.0/","headline":"","cross_cats":["nucl-th"],"primary_cat":"hep-ph","authors_text":"Hai-Qing Zhou, Hong-Yu Chen","submitted_at":"2013-12-02T02:57:04Z","abstract_excerpt":"A new form of two-photon exchange(TPE) effect is studied to explain the discrepancy between unpolarized and polarized experimental data in elastic $ep$ scattering. The mechanism is based on a simple idea that apart from the usual TPE effects from box and crossed-box diagrams, the mesons may also be exchanged in elastic $ep$ scattering by two-photon coupling at loop level. The detailed study shows such contributions to reduced unpolarized cross section ($\\sigma_{un}$) and polarized observables ($P_t,P_l$) at fixed $Q^2$ are only dependent on proton's electromagnetic form factors $G_{E,M}$ and a"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1312.0310","kind":"arxiv","version":4},"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"}