{"paper":{"title":"First Observation of the Direct Production of the $\\chi_{c1}$ in $e^+e^-$ Annihilation","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"hep-ex","authors_text":"BESIII Collaboration","submitted_at":"2022-03-25T17:04:38Z","abstract_excerpt":"We study the direct production of the $J^{PC}=1^{++}$ charmonium state $\\chi_{c1}(1P)$ in electron-positron annihilation by carrying out an energy scan around the mass of the $\\chi_{c1}(1P)$. The data were collected with the BESIII detector at the BEPCII collider. An interference pattern between the signal process $e^+e^-\\to \\chi_{c1}(1P) \\to \\gamma J/\\psi\\to\\gamma\\mu^+\\mu^-$ and the background processes $e^+e^-\\to \\gamma_{\\mathrm{ISR}} J/\\psi\\to\\gamma_{\\rm{ISR}}\\mu^+\\mu^-$ and $e^+e^-\\to\\gamma_{\\rm{ISR}}\\mu^+\\mu^-$ are observed by combining all the data samples. The $\\chi_{c1}(1P)$ signal is "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2203.13782","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2203.13782/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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"}