{"paper":{"title":"First observation of the P-wave spin-singlet bottomonium states h_b(1P) and h_b(2P)","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"hep-ex","authors_text":"Belle Collaboration","submitted_at":"2011-03-17T14:10:24Z","abstract_excerpt":"We report the first observation of the spin-singlet bottomonium states h_b(1P) and h_b(2P) produced in the reaction e+e- --> hb(nP)pi+pi- using a 121.4fb-1 data sample collected at energies near the Upsilon(5S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We determine M[h_b(1P)]=(9898.3+/-1.1+1.0-1.1) MeV/c^2 and M[h_b(2P)]=(10259.8+/-0.6+1.4-1.0) MeV/c^2,which correspond to P-wave hyperfine splittings Delta(M_HF) = (+1.6+/-1.5) MeV/c^2 and (+0.5+1.6-1.2) MeV/c^2, respectively. The h_b(1P) and h_b(2P) are observed with significances of 5.5sigma and 11.2sigma, "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1103.3419","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":""},"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"}