{"paper":{"title":"Observation of Direct CP Violation in K_{S,L} to \\pi \\pi Decays","license":"","headline":"","cross_cats":[],"primary_cat":"hep-ex","authors_text":"KTeV Collaboration","submitted_at":"1999-05-29T16:56:15Z","abstract_excerpt":"We have compared the decay rates of K_L and K_S to \\pi^+ \\pi^- and \\pi^0 \\pi^0 final states using a subset of the data from the KTeV experiment (E832) at Fermilab. We find that the direct-CP-violation parameter Re(\\epsilon'/\\epsilon) is equal to (28.0 \\pm 3.0 (stat) \\pm 2.8 (syst)) \\times 10^{-4}. This result definitively establishes the existence of CP violation in a decay process."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"hep-ex/9905060","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"}