{"paper":{"title":"Study of charmless hadronic B decays into the final states $K\\pi, \\pi\\pi$, and KK, with the first observation of $B \\to \\pi^+ \\pi^-$ and $B\\to K^0\\pi^0$","license":"","headline":"","cross_cats":[],"primary_cat":"hep-ex","authors_text":"CLEO Collaboration","submitted_at":"1999-08-08T05:07:04Z","abstract_excerpt":"We have studied charmless hadronic decays of B mesons into two-body final states with kaons and pions. We present preliminary results based on 9.66 million $B\\bar{B}$ pairs collected with the CLEO detector. We have made the first observation of the decay $B \\to \\pi^+\\pi^-$, with the branching fraction of $Br(B \\to \\pi^+ \\pi^-) = (4.7^{+1.8}_{-1.5} \\pm 0.6) \\times 10^{-6}$. We have also observed for the first time the decay $B \\to K^0\\pi^0$ with the branching fraction of $Br(B \\to K^0 \\pi^0) = (14.8^{+5.9+2.4}_{-5.1-3.3}) \\times 10^{-6}$, thus completing the set of four $K\\pi$ branching fractio"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"hep-ex/9908039","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"}