{"paper":{"title":"Search for CP and $P$ violating pseudoscalar decays into $\\pi\\pi$","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"hep-ex","authors_text":"et al, M. Ablikim, The BESIII Collaboration","submitted_at":"2011-06-25T09:41:52Z","abstract_excerpt":"Using a sample of $(225.2\\pm 2.8)\\times 10^6$ $J/\\psi$ events collected with the Beijing Spectrometer (BESIII) at the Beijing Electron-Positron Collider, CP and $P$ violating decays of $\\eta$, $\\eta'$ and $\\etac$ into $\\pi^+\\pi^-$ and $\\pi^0 \\pi^0$ are searched for in $\\jpsi$ radiative decays. No significant $\\eta$, $\\eta'$ or $\\etac$ signal is observed, and 90% confidence level upper limits of $\\BR(\\eta \\to \\pi^+\\pi^-)<3.9\\times 10^{-4}$, $\\BR(\\eta' \\to \\pi^+\\pi^-)<5.5\\times 10^{-5}$, $\\BR(\\etac \\to \\pi^+\\pi^-)<1.3\\times 10^{-4}$, $\\BR(\\eta \\to \\pi^0 \\pi^0)<6.9\\times 10^{-4}$, $\\BR(\\eta' \\to "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1106.5118","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"}