Precision tests of electron-muon universality with pions

Numao, T. and Aguilar-Arevalo, A. and Aoki, M. and Blecher, M. and Britton, D. I. and Bryman, D. A. and Chen, S. and Comfort, J. and Ding, M. M. and Doria, L. and Gumplinger, P. and Hussein, A. and Igarashi, Y. and Kettell, S. H. and Kurchaninov, L. and Littenberg, L. and Malbrunot, C. and Sher, A. and Sullivan, T. and Vavilov, V. and Yoshida, Y. and Yamada, K. (2012) Precision tests of electron-muon universality with pions. Il nuovo cimento C, 35 (4). pp. 63-67. ISSN 1826-9885

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The TRIUMF PIENU experiment aims to measure the branching ratio of pion decays, Re/μ = Γ(π → eν(γ))/Γ(π → μν(γ)), at a precision level of < 0.1%, confronting the Standard Model (SM) prediction of RSM e/μ = 1.2353(1) × 10−4. At that level, new physics beyond the SM involving mass scales up to 1000TeV may be heralded by an observed deviation from the precise SM expectation. Also, evidence of massive neutrinos in the π+ → e+ν decay spectrum has been sought with the background from π+ → μ+ → e+ decay chain highly suppressed. Upper limits (90% C.L.) on the neutrino mixing matrix element |Uei|2 in the mass region 65–130 MeV/c2 have been set at a 10−8 level.

Item Type: Article
Uncontrolled Keywords: Decays of π mesons ; Non-standard-model neutrinos, right-handed neutrinos, etc. ; Quark and lepton masses and mixing
Subjects: 500 Scienze naturali e Matematica > 530 Fisica
Depositing User: Marina Spanti
Date Deposited: 21 Apr 2020 18:17
Last Modified: 21 Apr 2020 18:17

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