@article{b0500c02e6be460caea8658763c143bf,
title = "Improved search for heavy neutrinos in the decay π →eν",
abstract = "A search for massive neutrinos has been made in the decay π+→e+ν. No evidence was found for extra peaks in the positron energy spectrum indicative of pion decays involving massive neutrinos (π→e+νh). Upper limits (90% C.L.) on the neutrino mixing matrix element |Uei|2 in the neutrino mass region 60-135 MeV/c2 were set and are an order of magnitude improvement over previous results.",
author = "{(PIENU Collaboration)} and A. Aguilar-Arevalo and M. Aoki and M. Blecher and Britton, {D. I.} and {Vom Bruch}, D. and Bryman, {D. A.} and S. Chen and J. Comfort and S. Cuen-Rochin and L. Doria and P. Gumplinger and A. Hussein and Y. Igarashi and S. Ito and S. Kettell and L. Kurchaninov and Littenberg, {L. S.} and C. Malbrunot and Mischke, {R. E.} and T. Numao and D. Protopopescu and A. Sher and T. Sullivan and D. Vavilov",
note = "Funding Information: This work was supported by the Natural Sciences and Engineering Research Council of Canada and TRIUMF through a contribution from the National Research Council of Canada and by Research Fund for Doctoral Program of Higher Education of China and was partially supported by KAKENHI (Grants No. 18540274 and No. 21340059) in Japan. M. B. was supported by US National Science Foundation Grant No. Phy-0553611. We are indebted to Brookhaven National Laboratory for the loan of the crystals. We would like to thank the TRIUMF detector, electronics, and DAQ groups for the extensive support. We would like to thank A. de Gouv{\^e}a and A. Kobach for providing useful information. Publisher Copyright: {\textcopyright} 2018 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the »https://creativecommons.org/licenses/by/4.0/» Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP.",
year = "2018",
month = apr,
day = "1",
doi = "10.1103/PhysRevD.97.072012",
language = "English",
volume = "97",
journal = "Physical Review D",
issn = "2470-0010",
publisher = "American Physical Society",
number = "7",
}