The PIENU experiment at TRIUMF : a sensitive probe for new physics

Malbrunot, C. et al. (2011) The PIENU experiment at TRIUMF : a sensitive probe for new physics. Journal of Physics: Conference Series, 312(10), 102010. (doi: 10.1088/1742-6596/312/10/102010)

Abstract

Study of rare decays is an important approach for exploring physics beyond the Standard Model (SM). The branching ratio of the helicity suppressed pion decays, R = , is one of the most accurately calculated decay process involving hadrons and has so far provided the most stringent test of the hypothesis of electron-muon universality in weak interactions. The branching ratio has been calculated in the SM to better than 0.01% accuracy to be R SM = 1.2353(1) × 10 . The PIENU experiment at TRIUMF, which started taking physics data in September 2009, aims to reach an accuracy five times better than the previous experiments, so as to confront the theoretical calculation at the level of ±0.1%. If a deviation from the RSM is found, "new physics" beyond the SM, at potentially very high mass scales (up to 1000 TeV), could be revealed. Alternatively, sensitive constraints on hypotheses can be obtained for interactions involving pseudoscalar or scalar interactions. So far, 4 million π + → e+ νe ue events have been accumulated by PIENU. This paper will outline the physics motivations, describe the apparatus and techniques designed to achieve high precision and present the latest results.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Britton, Professor David
• Authors: Malbrunot, C., Aguilar-Arevalo, A. A., Aoki, M., Blecher, M., Britton, D. I., Bryman, D. A., Chen, S., Comfort, J., Ding, M., Doornbos, J., Doria, L., Gumplinger, P., Hurst, C., Hussein, A., Igarashi, Y., Ito, N., Kettell, S., Kuno, Y., Kurchaninov, L., Littenberg, L., Numao, T., Poutissou, R., Sher, A., Sullivan, T., Vavilov, D., Yamada, K., and Yoshida, M.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Journal of Physics: Conference Series
• Publisher: IOP Publishing
• ISSN: 1742-6588
• ISSN (Online): 1742-6596
• Copyright Holders: Copyright 2010 The Authors
• First Published: First published in Journal of Physics: Conference Series 312(10):102010
• Publisher Policy: Published under licence by IOP Publishing Ltd