{"paper":{"title":"Improved measurement of the $\\pi \\rightarrow \\mbox{e} \\nu$ branching ratio","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"hep-ex","authors_text":"A.Aguilar-Arevalo, A. Hussein, A. Sher, C. Malbrunot, D.A. Bryman, D.I. Britton, D. Protopopescu, D. Vavilov, D. vom Bruch, J. Comfort, K. Yamada, L. Doria, L. Kurchaninov, L.S. Littenberg, M. Aoki, M. Blecher, M. Ding, P. Gumplinger, R.E. Mischke, S. Chen, S. Cuen-Rochin, S.H. Kettell, S. Ito, T. Numao, T. Sullivan, Y. Igarashi","submitted_at":"2015-06-18T22:48:18Z","abstract_excerpt":"A new measurement of the branching ratio, $R_{e/\\mu} =\\Gamma (\\pi^+ \\rightarrow \\mbox{e}^+ \\nu + \\pi^+ \\rightarrow \\mbox{e}^+ \\nu \\gamma)/ \\Gamma (\\pi^+ \\rightarrow \\mu^+ \\nu + \\pi^+ \\rightarrow \\mu^+ \\nu \\gamma)$, resulted in $R_{e/\\mu}^{exp} = (1.2344 \\pm 0.0023 (stat) \\pm 0.0019 (syst)) \\times 10^{-4}$. This is in agreement with the standard model prediction and improves the test of electron-muon universality to the level of 0.1 %."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1506.05845","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"}