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Article
Report number	arXiv:1609.03637
Title	A new search for the $K_{L} \to \pi^0 \nu \overline{\nu}$ and $K_{L} \to \pi^{0} X^{0}$ decays
Related title	A New Search for the $K_{L} \to \pi^0 \nu \overline{\nu}$ and $K_{L} \to \pi^{0} X^{0}$ decays
Author(s)	Ahn, J.K. (Pusan Natl. U.) ; Baek, K.Y. (Pusan Natl. U.) ; Banno, S. (Osaka U.) ; Beckford, B. (Tohoku U.) ; Brubaker, B. (Yale U.) ; Cai, T. (Rochester U.) ; Campbell, M. (CERN) ; Carruth, C. ; Chen, S.H. ; Chu, S. (Stanford U., Phys. Dept.) ; Comfort, J. (Arizona State U.) ; Duh, Y.T. (Taiwan, Natl. Taiwan U.) ; Furukawa, T. (Bern U., LHEP) ; Haraguchi, H. ; Hineno, T. (Kyoto U.) ; Hsiung, Y.B. (Taiwan, Natl. Taiwan U.) ; Hutcheson, M. ; Inagaki, T. (JAERI-RIKEN, Hyogo) ; Isoe, M. ; Iwai, E. (KEK, Tsukuba) ; Kamibayashi, T. ; Kamiji, I. ; Kawasaki, N. (Kyoto U.) ; Kim, E.J. (Chonbuk Natl. U.) ; Kim, Y.J. (Los Alamos) ; Ko, J.W. (Unlisted, KR) ; Komatsubara, T.K. (KEK, Tsukuba) ; Kurilin, A.S. (Minsk, High Energy Phys. Ctr.) ; Lee, G.H. (Chonbuk Natl. U.) ; Lee, H.S. (Florida U. ; Wisconsin U., Madison) ; Lee, J.W. (Mainz U., Inst. Kernphys.) ; Lee, S.K. (Chonbuk Natl. U. ; SUNY, Stony Brook) ; Lim, G.Y. (KEK, Tsukuba) ; Lin, C. (Beijing, Inst. High Energy Phys.) ; Ma, J. (Beijing, Inst. High Energy Phys.) ; Maeda, Y. (Tohoku U.) ; Masuda, T. (Kyoto U.) ; Matsumura, T. (Nippon NTT, Kanagawa) ; Mcfarland, D. (Arizona State U.) ; Micallef, J. ; Miyazaki, K. (Kobe U.) ; Morgan, K. (SSCL) ; Murayama, R. (Osaka U.) ; Naito, D. (Kyoto U.) ; Nakagiri, K. (Kyoto U. (main)) ; Nakajima, Y. (LBL, Berkeley) ; Nakaya, Y. (Osaka U.) ; Nanjo, H. (Hirosaki U.) ; Nomura, T. (Yamagata U.) ; Odani, Y. (Saga U., Japan) ; Ogata, R. (Saga U., Japan) ; Okuno, H. (KEK, Tsukuba) ; Ota, T. ; Ri, Y.D. (Tokyo Metropolitan U.) ; Sasaki, M. (NASA, Goddard) ; Sasao, N. (Kyoto U.) ; Sato, K. (Tsukuba U.) ; Sato, T. (KEK, Tsukuba) ; Seki, S. (Kyoto U.) ; Shimogawa, T. (Saga U., Japan) ; Shinkawa, T. (KEK, Tsukuba) ; Shinohara, S. (Kyoto U.) ; Shiomi, K. (Kyoto U.) ; Son, J.S. (Chonbuk Natl. U.) ; Stevens, J. (Jefferson Lab) ; Su, S. (Arizona U.) ; Sugiyama, Y. (Unlisted) ; Suzuki, S. (KEK, Tsukuba) ; Tajima, Y. (Yamagata U.) ; Takahashi, G. (Kyoto U.) ; Takashima, Y. ; Tecchio, M. (Michigan U.) ; Teo, I. ; Togawa, M. (Kyoto U.) ; Toyoda, T. (Osaka U.) ; Tung, Y.C. (Taiwan, Natl. Taiwan U.) ; Usuki, T. ; Wah, Y.W. (Chicago U., EFI) ; Watanabe, H. (KEK, Tsukuba) ; Whallon, N. ; Woo, J.K. (Unlisted, KR) ; Xu, J. (Princeton U.) ; Yamaga, M. (Tohoku U.) ; Yamamoto, S. (Tokyo Metropolitan U., Math. Dept.) ; Yamanaka, T. (Tokyo U., ICEPP) ; Yamauchi, H. (Tohoku U.) ; Yanagida, Y. (Osaka U.) ; Yokota, H. (Nara U.) ; Yoshida, H.Y. ; Yoshimoto, H. (Osaka U.)
Publication	2017
Imprint	12 Sep 2016
Number of pages	11
Note	11 pages, 5 figures, to be published in PTEP
In:	Prog. Theor. Exp. Phys. 2017 (2017) 021C01
DOI	10.1093/ptep/ptx001
Subject category	hep-ex ; Particle Physics - Experiment
Abstract	We searched for the $CP$-violating rare decay of neutral kaon, $K_{L} \to \pi^0 \nu \overline{\nu}$, in data from the first 100 hours of physics running in 2013 of the J-PARC KOTO experiment. One candidate event was observed while $0.34\pm0.16$ background events were expected. We set an upper limit of $5.1\times10^{-8}$ for the branching fraction at the 90\% confidence level (C.L.). An upper limit of $3.7\times10^{-8}$ at the 90\% C.L. for the $K_{L} \to \pi^{0} X^{0}$decay was also set for the first time, where $X^{0}$ is an invisible particle with a mass of 135 MeV/$c^{2}$.
Copyright/License	arXiv nonexclusive-distrib. 1.0 publication: © 2017-2024 The Author(s) (License: CC-BY-4.0)

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