Initial results from the PIENU experiment

Sullivan, T. et al. (2017) Initial results from the PIENU experiment. Hyperfine Interactions, 238(1), 3. (doi: 10.1007/s10751-016-1367-5)

Abstract

The pion branching ratio, Rπ=Γ(π+→e+νe+π+→e+νeγ)Γ(π+→μ+νμ+π+→μ+νμγ)Rπ=Γ(π+→e+νe+π+→e+νeγ)Γ(π+→μ+νμ+π+→μ+νμγ) , provides a sensitive test of lepton universality and constraints on many new physics scenarios. The theoretical uncertainty on the Standard Model prediction of Rπ is 0.02 %, a factor of twenty smaller than the experimental uncertainty. The analysis of a subset of data taken by the PIENU experiment will be presented. The result, Rπ = (1.2344 ± 0.0023(stat) ± 0.0019(syst)) ⋅ 10−4 [1], is consistent with the Standard Model prediction and represents a 0.1 % constraint on lepton non-universality.

• Item Type: Articles
• Additional Information: This article is part of the Topical Collection on Proceedings of the 6th International Symposium on Symmetries in Subatomic Physics (SSP 2015), Victoria, Canada, 8–12 June 2015.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Protopopescu, Dr Dan and Britton, Professor David
• Authors: Sullivan, T., Aguilar-Arevalo, A., Aoki, M., Blecher, M., Britton, D.i., Bryman, D.A., Bruch, D. v., Chen, S., Comfort, J., Cuen-Rochin, S., Doria, L., Gumplinger, P., Hussein, A., Igarashi, Y., Ito, S., Kettell, S. H., Kurchaninov, L., Littenberg, L. S., Malbrunot, C., Mischke, R. E., Numao, T., Protopopescu, D., Sher, A., and Vavilov, D.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Hyperfine Interactions
• Publisher: Springer
• ISSN: 0304-3843
• ISSN (Online): 1572-9540
• Published Online: 06 December 2016