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Ahn JK, Beckford B, Campbell M, Chen SH, Comfort J, Dona K, Farrington MS, Hanai K, Hara N, Haraguchi H, Hsiung YB, Hutcheson M, Inagaki T, Isoe M, Kamiji I, Kato T, Kim EJ, Kim JL, Kim HM, Komatsubara TK, Kotera K, Lee SK, Lee JW, Lim GY, Lin QS, Lin C, Luo Y, Mari T, Masuda T, Matsumura T, Mcfarland D, McNeal N, Miyazaki K, Murayama R, Nakagiri K, Nanjo H, Nishimiya H, Noichi Y, Nomura T, Nunes T, Ohsugi M, Okuno H, Redeker JC, Sanchez J, Sasaki M, Sasao N, Sato T, Sato K, Sato Y, Shimizu N, Shimogawa T, Shinkawa T, Shinohara S, Shiomi K, Shiraishi R, Su S, Sugiyama Y, Suzuki S, Tajima Y, Taylor M, Tecchio M, Togawa M, Toyoda T, Tung YC, Vuong QH, Wah YW, Watanabe H, Yamanaka T, Yoshida HY, Zaidenberg L. Study of the K_{L}→π^{0}νν[over ¯] Decay at the J-PARC KOTO Experiment. Phys Rev Lett 2021; 126:121801. [PMID: 33834796 DOI: 10.1103/physrevlett.126.121801] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 02/18/2021] [Indexed: 06/12/2023]
Abstract
The rare decay K_{L}→π^{0}νν[over ¯] was studied with the dataset taken at the J-PARC KOTO experiment in 2016, 2017, and 2018. With a single event sensitivity of (7.20±0.05_{stat}±0.66_{syst})×10^{-10}, three candidate events were observed in the signal region. After unveiling them, contaminations from K^{±} and scattered K_{L} decays were studied, and the total number of background events was estimated to be 1.22±0.26. We conclude that the number of observed events is statistically consistent with the background expectation. For this dataset, we set an upper limit of 4.9×10^{-9} on the branching fraction of K_{L}→π^{0}νν[over ¯] at the 90% confidence level.
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Affiliation(s)
- J K Ahn
- Department of Physics, Korea University, Seoul 02841, Republic of Korea
| | - B Beckford
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - M Campbell
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - S H Chen
- Department of Physics, National Taiwan University, Taipei, Taiwan 10617, Republic of China
| | - J Comfort
- Department of Physics, Arizona State University, Tempe, Arizona 85287, USA
| | - K Dona
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - M S Farrington
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - K Hanai
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - N Hara
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - H Haraguchi
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Y B Hsiung
- Department of Physics, National Taiwan University, Taipei, Taiwan 10617, Republic of China
| | - M Hutcheson
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - T Inagaki
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - M Isoe
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - I Kamiji
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - T Kato
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - E J Kim
- Division of Science Education, Jeonbuk National University, Jeonju 54896, Republic of Korea
| | - J L Kim
- Division of Science Education, Jeonbuk National University, Jeonju 54896, Republic of Korea
| | - H M Kim
- Division of Science Education, Jeonbuk National University, Jeonju 54896, Republic of Korea
| | - T K Komatsubara
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - K Kotera
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - S K Lee
- Division of Science Education, Jeonbuk National University, Jeonju 54896, Republic of Korea
| | - J W Lee
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - G Y Lim
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - Q S Lin
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - C Lin
- Department of Physics, National Taiwan University, Taipei, Taiwan 10617, Republic of China
| | - Y Luo
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - T Mari
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - T Masuda
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
| | - T Matsumura
- Department of Applied Physics, National Defense Academy, Kanagawa 239-8686, Japan
| | - D Mcfarland
- Department of Physics, Arizona State University, Tempe, Arizona 85287, USA
| | - N McNeal
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - K Miyazaki
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - R Murayama
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - K Nakagiri
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - H Nanjo
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - H Nishimiya
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Y Noichi
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - T Nomura
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - T Nunes
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - M Ohsugi
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - H Okuno
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - J C Redeker
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - J Sanchez
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - M Sasaki
- Department of Physics, Yamagata University, Yamagata 990-8560, Japan
| | - N Sasao
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
| | - T Sato
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - K Sato
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Y Sato
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - N Shimizu
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - T Shimogawa
- Department of Physics, Saga University, Saga 840-8502, Japan
| | - T Shinkawa
- Department of Applied Physics, National Defense Academy, Kanagawa 239-8686, Japan
| | - S Shinohara
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - K Shiomi
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - R Shiraishi
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - S Su
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Y Sugiyama
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - S Suzuki
- Department of Physics, Saga University, Saga 840-8502, Japan
| | - Y Tajima
- Department of Physics, Yamagata University, Yamagata 990-8560, Japan
| | - M Taylor
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - M Tecchio
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - M Togawa
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - T Toyoda
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Y-C Tung
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - Q H Vuong
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Y W Wah
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - H Watanabe
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - T Yamanaka
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - H Y Yoshida
- Department of Physics, Yamagata University, Yamagata 990-8560, Japan
| | - L Zaidenberg
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
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Ahn JK, Beckford B, Beechert J, Bryant K, Campbell M, Chen SH, Comfort J, Dona K, Hara N, Haraguchi H, Hsiung YB, Hutcheson M, Inagaki T, Kamiji I, Kawasaki N, Kim EJ, Kim JL, Kim YJ, Ko JW, Komatsubara TK, Kotera K, Kurilin AS, Lee JW, Lim GY, Lin C, Lin Q, Luo Y, Ma J, Maeda Y, Mari T, Masuda T, Matsumura T, Mcfarland D, McNeal N, Micallef J, Miyazaki K, Murayama R, Naito D, Nakagiri K, Nanjo H, Nishimiya H, Nomura T, Ohsugi M, Okuno H, Sasaki M, Sasao N, Sato K, Sato T, Sato Y, Schamis H, Seki S, Shimizu N, Shimogawa T, Shinkawa T, Shinohara S, Shiomi K, Su S, Sugiyama Y, Suzuki S, Tajima Y, Taylor M, Tecchio M, Togawa M, Tung YC, Wah YW, Watanabe H, Woo JK, Yamanaka T, Yoshida HY. Search for K_{L}→π^{0}νν[over ¯] and K_{L}→π^{0}X^{0} Decays at the J-PARC KOTO Experiment. Phys Rev Lett 2019; 122:021802. [PMID: 30720307 DOI: 10.1103/physrevlett.122.021802] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 12/14/2018] [Indexed: 06/09/2023]
Abstract
A search for the rare decay K_{L}→π^{0}νν[over ¯] was performed. With the data collected in 2015, corresponding to 2.2×10^{19} protons on target, a single event sensitivity of (1.30±0.01_{stat}±0.14_{syst})×10^{-9} was achieved and no candidate events were observed. We set an upper limit of 3.0×10^{-9} for the branching fraction of K_{L}→π^{0}νν[over ¯] at the 90% confidence level (C.L.), which improved the previous limit by almost an order of magnitude. An upper limit for K_{L}→π^{0}X^{0} was also set as 2.4×10^{-9} at the 90% C.L., where X^{0} is an invisible boson with a mass of 135 MeV/c^{2}.
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Affiliation(s)
- J K Ahn
- Department of Physics, Korea University, Seoul 02841, Republic of Korea
| | - B Beckford
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - J Beechert
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - K Bryant
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - M Campbell
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - S H Chen
- Department of Physics, National Taiwan University, Taipei, Taiwan 10617, Republic of China
| | - J Comfort
- Department of Physics, Arizona State University, Tempe, Arizona 85287, USA
| | - K Dona
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - N Hara
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - H Haraguchi
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Y B Hsiung
- Department of Physics, National Taiwan University, Taipei, Taiwan 10617, Republic of China
| | - M Hutcheson
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - T Inagaki
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - I Kamiji
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - N Kawasaki
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - E J Kim
- Division of Science Education, Chonbuk National University, Jeonju 54896, Republic of Korea
| | - J L Kim
- Department of Physics, Korea University, Seoul 02841, Republic of Korea
| | - Y J Kim
- Department of Physics, Jeju National University, Jeju 63243, Republic of Korea
| | - J W Ko
- Department of Physics, Jeju National University, Jeju 63243, Republic of Korea
| | - T K Komatsubara
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - K Kotera
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - A S Kurilin
- Laboratory of Nuclear Problems, Joint Institute for Nuclear Researches, Dubna, Moscow region 141980, Russia
| | - J W Lee
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - G Y Lim
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - C Lin
- Department of Physics, National Taiwan University, Taipei, Taiwan 10617, Republic of China
| | - Q Lin
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - Y Luo
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - J Ma
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - Y Maeda
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - T Mari
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - T Masuda
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - T Matsumura
- Department of Applied Physics, National Defense Academy, Kanagawa 239-8686, Japan
| | - D Mcfarland
- Department of Physics, Arizona State University, Tempe, Arizona 85287, USA
| | - N McNeal
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - J Micallef
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - K Miyazaki
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - R Murayama
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - D Naito
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - K Nakagiri
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - H Nanjo
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - H Nishimiya
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - T Nomura
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - M Ohsugi
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - H Okuno
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - M Sasaki
- Department of Physics, Yamagata University, Yamagata 990-8560, Japan
| | - N Sasao
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
| | - K Sato
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - T Sato
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - Y Sato
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - H Schamis
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - S Seki
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - N Shimizu
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - T Shimogawa
- Department of Physics, Saga University, Saga 840-8502, Japan
| | - T Shinkawa
- Department of Applied Physics, National Defense Academy, Kanagawa 239-8686, Japan
| | - S Shinohara
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - K Shiomi
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - S Su
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Y Sugiyama
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - S Suzuki
- Department of Physics, Saga University, Saga 840-8502, Japan
| | - Y Tajima
- Department of Physics, Yamagata University, Yamagata 990-8560, Japan
| | - M Taylor
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - M Tecchio
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - M Togawa
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Y C Tung
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - Y W Wah
- Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - H Watanabe
- Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - J K Woo
- Department of Physics, Jeju National University, Jeju 63243, Republic of Korea
| | - T Yamanaka
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - H Y Yoshida
- Department of Physics, Yamagata University, Yamagata 990-8560, Japan
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