{"paper":{"title":"Detector for measuring the $\\pi^+\\to e^+\\nu_e$ branching fraction","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["hep-ex"],"primary_cat":"physics.ins-det","authors_text":"A. A. Aguilar-Arevalo, A. Hussein, A. Muroi, A. Sher, C. Malbrunot, D. Bryman, D. Vavilov, D. vom Bruch, G. Sheffer, J. Comfort, K. Tauchi, K. Yamada, L. Doria, L. Kurchaninov, L. Littenberg, M. Aoki, M. Blecher, M. Yoshida, N. Ito, P. Gumplinger, R.E. Mischke, S. Cuen-Rochin, S. H. Kettell, S. Ito, T. Numao, T. Sullivan, Y. Igarashi","submitted_at":"2015-05-11T19:07:51Z","abstract_excerpt":"The PIENU experiment at TRIUMF is aimed at a measurement of the branching ratio $R^{e/\\mu}$ = ${\\Gamma\\big((\\pi^{+} \\rightarrow e^{+} \\nu_{e}) + (\\pi^{+} \\rightarrow e^{+} \\nu_{e}\\gamma)\\big)}/{\\Gamma\\big((\\pi^{+} \\rightarrow \\mu^{+} \\nu_{\\mu})+(\\pi^{+} \\rightarrow \\mu^{+} \\nu_{\\mu}\\gamma)\\big)}$ with precision $<$0.1\\%. Incident pions, delivered at the rate of 60 kHz with momentum 75 MeV/c, were degraded and stopped in a plastic scintillator target. Pions and their decay product positrons were detected with plastic scintillators and tracked with multiwire proportional chambers and silicon str"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1505.02737","kind":"arxiv","version":1},"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"}