1. Study of the KL→π0νν¯ Decay at the J-PARC KOTO Experiment
- Author
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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, Y-C, Vuong, QH, Wah, YW, Watanabe, H, Yamanaka, T, Yoshida, HY, and Zaidenberg, L
- Subjects
Particle and High Energy Physics ,Physical Sciences ,KOTO Collaboration ,hep-ex ,Mathematical Sciences ,Engineering ,General Physics ,Mathematical sciences ,Physical sciences - 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.
- Published
- 2021