{"paper":{"title":"Precision muon decay measurements and improved constraints on the weak interaction","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"hep-ex","authors_text":"A. Gaponenko, A. Grossheim, A. Olin, B. Shin, C. A. Gagliardi, D. D. Koetke, D. R. Gill, E. L. Mathie, G. M. Marshall, G. Sheffer, J. F. Bueno, J. Hu, J.-M. Poutissou, K. Olchanski, M. D. Hasinoff, P. Depommier, P. Gumplinger, R. Bayes, R. E. Mischke, R. E. Tribble, R. Openshaw, R. P. MacDonald, R. Poutissou, R. S. Henderson, R. Tacik, T. D. S. Stanislaus, TWIST Collaboration: A. Hillairet, V. Selivanov, W. Faszer, Yu. I. Davydov","submitted_at":"2011-12-15T18:59:51Z","abstract_excerpt":"The TWIST Collaboration has completed its measurement of the three muon decay parameters \\rho, \\delta, and P_\\mu\\xi. This paper describes our determination of \\rho, which governs the shape of the overall momentum spectrum, and \\delta, which controls the momentum dependence of the parity-violating decay asymmetry. The results are \\rho=0.74977\\pm 0.00012(stat.)\\pm 0.00023(syst.) and \\delta = 0.75049\\pm 0.00021(stat.)\\pm 0.00027(syst.). These are consistent with the value of 3/4 given for both parameters in the standard model, and each is over a factor of 10 more precise than the measurements pub"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1112.3606","kind":"arxiv","version":3},"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"}