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arXiv · 1411.3963

Search for heavy neutrinos in $K^+\toμ^+ν_H$ decays

Abstract

Evidence of a heavy neutrino, $ν_H$, in the $K^+\toμ^+ν_H$ decays was sought using the E949 experimental data with an exposure of $1.70\times 10^{12}$ stopped kaons. With the major background from the radiative $K^+\toμ^+ν_μγ$ decay understood and suppressed, upper limits (90% C.L.) on the neutrino mixing matrix element between muon and heavy neutrino, $|U_{μH}|^2$, were set at the level of $10^{-7}$ to $10^{-9}$ for the heavy neutrino mass region 175 to 300 MeV/$c^2$.

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A. V. Artamonov, B. Bassalleck, B. Bhuyan, E. W. Blackmore, D. A. Bryman, S. Chen, I-H. Chiang, I. -A. Christidi, P. S. Cooper, M. V. Diwan, J. S. Frank, T. Fujiwara, J. Hu, J. Ives, A. O. Izmaylov, D. E. Jaffe, S. Kabe, S. H. Kettell, M. M. Khabibullin, A. N. Khotjantsev, P. Kitching, M. Kobayashi, T. K. Komatsubara, A. Konaka, Yu. G. Kudenko, L. G. Landsberg, B. Lewis, K. K. Li, L. S. Littenberg, J. A. Macdonald, J. Mildenberger, O. V. Mineev, M. Miyajima, K. Mizouchi, N. Muramatsu, T. Nakano, M. Nomachi, T. Nomura, T. Numao, V. F. Obraztsov, K. Omata, D. I. Patalakha, R. Poutissou, G. Redlinger, T. Sato, T. Sekiguchi, A. T. Shaikhiev, T. Shinkawa, R. C. Strand, S. Sugimoto, Y. Tamagawa, R. Tschirhart, T. Tsunemi, D. V. Vavilov, B. Viren, Zhe Wang, Hanyu Wei, N. V. Yershov, Y. Yoshimura, T. Yoshioka. 2015-02-11. Search for heavy neutrinos in $K^+\toμ^+ν_H$ decays. https://doi.org/10.1103/physrevd.91.052001

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