학술논문
Study of the KL→π0νν¯ Decay at the J-PARC KOTO Experiment
Document Type
article
Author
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; Zaidenberg, L
Source
Physical Review Letters. 126(12)
Subject
Language
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.