{"paper":{"title":"Search for the decay $K^+\\to \\pi^+ \\nu \\bar\\nu$ in the momentum region $P_\\pi < 195 {\\rm ~MeV/c}$","license":"","headline":"","cross_cats":[],"primary_cat":"hep-ex","authors_text":"E787 collaboration","submitted_at":"2002-01-23T17:11:18Z","abstract_excerpt":"We have searched for the decay $K^+ \\to \\pi^+ \\nu \\bar\\nu$ in the kinematic region with pion momentum below the $K^+ \\to \\pi^+ \\pi^0$ peak. One event was observed, consistent with the background estimate of $0.73\\pm 0.18$. This implies an upper limit on $B(K^+ \\to \\pi^+ \\nu \\bar\\nu)< 4.2\\times 10^{-9}$ (90% C.L.), consistent with the recently measured branching ratio of $(1.57^{+1.75}_{-0.82}) \\times 10^{-10}$, obtained using the standard model spectrum and the kinematic region above the $K^+ \\to \\pi^+ \\pi^0$ peak. The same data were used to search for $K^+ \\to \\pi^+ X^0$, where $X^0$ is a wea"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"hep-ex/0201037","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"}