{"paper":{"title":"Measurement of the Muon Decay Parameter delta","license":"","headline":"","cross_cats":[],"primary_cat":"hep-ex","authors_text":"7, A.A. Krushinsky, A. Olin, B. Jamieson, B. Shin, C.A. Gagliardi, D.D. Koetke, D.H. Wright, D.R. Gill, E.L. Mathie, F. Sobratee, G.M. Marshall, G. Sheffer, J.A. Macdonald, J. Doornbos, J. Hu, J.-M. Poutissou, J.R. Musser, K. Olchanski, L.V. Miasoedov, M.A. Quraan, M.A. Vasiliev, M.C. Fujiwara, M.D. Hasinoff, M. Nozar, N.L. Rodning, P. Depommier, P. Green, P. Gumplinger, P. Kitching, P.M. Nord, R. Bayes, R.E. Mischke, R.E. Tribble, R. Openshaw, R.P. MacDonald, R. Poutissou, R.S. Henderson, R. Tacik, T.A. Porcelli, T.D.S. Stanislaus, TWIST Collaboration: A. Gaponenko, V.D. Torokhov, V. Selivanov, W. Faszer, Yu.I. Davydov, Yu.Yu. Lachin","submitted_at":"2004-10-17T21:08:49Z","abstract_excerpt":"The muon decay parameter delta has been measured by the TWIST collaboration. We find delta = 0.74964 +- 0.00066(stat.) +- 0.00112(syst.), consistent with the Standard Model value of 3/4. This result implies that the product Pmuxi of the muon polarization in pion decay, Pmu, and the muon decay parameter xi falls within the 90% confidence interval 0.9960 < Pmuxi < xi < 1.0040. It also has implications for left-right-symmetric and other extensions of the Standard Model."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"hep-ex/0410045","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/hep-ex/0410045/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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"}