{"paper":{"title":"$J/\\psi \\to \\gamma\\eta'\\pi^+\\pi^-$ and the structure observed around the $\\bar pp$ threshold","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["nucl-th"],"primary_cat":"hep-ph","authors_text":"Johann Haidenbauer, Ling-Yun Dai, Ulf-G. Mei{\\ss}ner","submitted_at":"2018-04-19T10:48:01Z","abstract_excerpt":"We analyze the origin of the structure observed in the reaction $J/\\psi \\to \\gamma \\eta'\\pi^+\\pi^-$ for $\\eta'\\pi^+\\pi^-$ invariant masses close to the antiproton-proton ($\\bar pp$) threshold, commonly associated with the $X(1835)$ resonance. Specifically, we explore the effect of a possible contribution from the two-step process $J/\\psi \\to \\gamma \\bar NN \\to \\gamma \\eta'\\pi^+\\pi^-$. The calculation is performed in distorted-wave Born approximation which allows an appropriate inclusion of the $\\bar NN$ interaction in the transition amplitude. The $\\bar NN$ amplitude itself is generated from a"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1804.07077","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"}