{"paper":{"title":"Constrain the UT angle $\\gamma$ by CP violation parameters in $B^0 \\to \\pi^+ \\pi^-$","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["hep-ex"],"primary_cat":"hep-ph","authors_text":"Cai-Dian L\\\"u, Qin Qin, Ying Li, Zhi-Tian Zou","submitted_at":"2015-06-08T08:40:07Z","abstract_excerpt":"We calculate the tree and penguin amplitudes in the $B^0\\to\\pi^+\\pi^-$ decay channel employing the perturbative QCD factorization approach. Using the amplitudes as input with the theoretical uncertainties sufficiently considered, we constrain the UT angle $\\gamma$ to $53^\\circ\\leq\\gamma\\leq70^\\circ$, from the measurements of the CP violation parameters $C_{\\pi^+\\pi^-}$ and $S_{\\pi^+\\pi^-}$ in $B^0\\to\\pi^+\\pi^-$. The U-spin breaking effect between $B^0\\to\\pi^+\\pi^-$ and $B_s^0\\to K^+K^-$ is estimated to be around 30\\%."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1506.02398","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"}