{"paper":{"title":"Observation of the decay $B_s^0\\to J/\\psi\\eta$ and Evidence for $B_s^0\\to J/\\psi\\eta'$","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"hep-ex","authors_text":"The Belle Collaboration","submitted_at":"2009-12-08T08:55:18Z","abstract_excerpt":"We report the first observation of $B_s^0\\to J/\\psi\\eta$ and evidence for $B_s^0\\to J/\\psi\\eta'$. These results are obtained from $23.6 \\mathrm{fb}^{-1}$ of data collected at the $\\Upsilon(5S)$ resonance with the Belle detector at the KEKB $e^+e^-$ collider. We measure the branching fractions $\\mathcal{B}(B_s^0\\to J/\\psi\\eta)= (3.32 \\pm 0.87(\\mathrm{stat.})^{+0.32}_{-0.28}(\\mathrm{syst.}) \\pm 0.42(f_s))\\times 10^{-4}}$ with a significance of $7.3 \\sigma$, and $\\mathcal{B}(B_s^0\\to J/\\psi\\eta')= (3.1 \\pm 1.2(\\mathrm{stat.})^{+0.5}_{-0.6}(\\mathrm{syst.}) \\pm 0.38(f_s))\\times 10^{-4}$ with a sign"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0912.1434","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"}