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arXiv · 1712.03275

Improved Search for Heavy Neutrinos in the Decay $\pi\rightarrow e\nu$

A. Aguilar-Arevalo·M. Aoki·M. Blecher·D. I. Britton·D. vom Bruch·D. A. Bryman·S. Chen·J. Comfort·S. Cuen-Rochin·L. Doria·P. Gumplinger·A. Hussein·Y. Igarashi·S. Ito·S. Kettell·L. Kurchaninov·L. S. Littenberg·C. Malbrunot·R. E. Mischke·T. Numao·D. Protopopescu·A. Sher·T. Sullivan·D. Vavilov
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Abstract

A search for massive neutrinos has been made in the decay $\pi\rightarrow e^+ \nu$. No evidence was found for extra peaks in the positron energy spectrum indicative of pion decays involving massive neutrinos ($\pi\rightarrow e^+ \nu_h$). Upper limits (90 \% C.L.) on the neutrino mixing matrix element $|U_{ei}|^2$ in the neutrino mass region 60--135 MeV/$c^2$ were set, which are %representing an order of magnitude improvement over previous results.

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A. Aguilar-Arevalo, M. Aoki, M. Blecher, D. I. Britton, D. vom Bruch, D. A. Bryman, S. Chen, J. Comfort, S. Cuen-Rochin, L. Doria, P. Gumplinger, A. Hussein, Y. Igarashi, S. Ito, S. Kettell, L. Kurchaninov, L. S. Littenberg, C. Malbrunot, R. E. Mischke, T. Numao, D. Protopopescu, A. Sher, T. Sullivan, D. Vavilov. 2017-12-08. Improved Search for Heavy Neutrinos in the Decay $\pi\rightarrow e\nu$. https://doi.org/10.1103/physrevd.97.072012

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