Search for the K L → π 0 ν ν ¯ Decay at the J-PARC KOTO Experiment
Year: 2025
Type: article
Abstract: We performed a search for the K_{L}→π^{0}νν[over ¯] decay using the data taken in 2021 at the J-PARC KOTO experiment. With newly installed counters and new analysis method, the expected background was suppressed to 0.252±0.055_{stat} _{-0.067^{syst}}^{+0.052}. With a single event sensitivity of (9.33±0.06_{stat}±0.84_{syst})×10^{-10}, no events were observed in the signal region. An upper limit on the branching fraction for the decay was set to be 2.2×10^{-9} at the 90% confidence level (C.L.), which improved the previous upper limit from KOTO by a factor of 1.4. With the same data, a search for K_{L}→π^{0}X^{0} was also performed, where X^{0} is an invisible boson with a mass ranging from 1 to 260 MeV/c^{2}. For X^{0} with a mass of 135 MeV/c^{2}, an upper limit on the branching fraction of K_{L}→π^{0}X^{0} was set to be 1.6×10^{-9} at the 90% C.L.
Source: Physical Review Letters
Authors: J. K. Ahn, M. Farrington, M. Gonzalez, N. Grethen, K. Hanai, N. Hara, H. Haraguchi, Y. B. Hsiung, T. Inagaki, M. Katayama, T. Kato, Y. Kawata, E. J. Kim, H. M. Kim, A. Kitagawa, T. K. Komatsubara, K. Kotera, S. K. Lee, X. Li, G. Y. Lim, C. Lin, Y. Luo, T. Mari, T. Matsumura, I. Morioka, H. Nanjo, H. Nishimiya, Y. Noichi, T. Nomura, K. Ono, M. Osugi, P. Paschos, J. Redeker, T. Sato, Y. Sato, T. Shibata, N. Shimizu, T. Shinkawa, K. Shiomi, R. Shiraishi, S. Suzuki, Y. Tajima, N. Taylor, Y. C. Tung, Y. W. Wah, H. Watanabe, T. Wu, T. Yamanaka, H. Y. Yoshida
Institutions: Korea University, University of Chicago, The University of Osaka, National Taiwan University, High Energy Accelerator Research Organization, Institute of Particle and Nuclear Studies, Jeonbuk National University, Japan Proton Accelerator Research Complex, National Defense Academy of Japan, Saga University, Yamagata University
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,750
Funders: National Science and Technology Council, U.S. Department of Energy, Ministry of Education, Ministry of Education, Culture, Sports, Science and Technology, National Research Foundation of Korea, Ministry of Education, India, Office of Science, Computation Institute, University of Chicago, Japan Society for the Promotion of Science, High Energy Physics
Awards: Enhancement of functionalities of the neutral beam line for rare Kaon decay search, G1626428022, G1737725155, G1883778784, Development of charged particle detector for KOTO experiment, 荷電粒子を伴う中性K中間子崩壊を通じた新物理探索のための検出器開発, Search for new physics in particle physics with world-highest sensitivity of neutral kaon experiment, G4833769319, G4860224801, Search for New Physics in Rare Kaon Decays, RARE KAON DECAYS AT J-PARC, Searching for new physics beyond the standard model with four dimensitonal caloriemter, G8204040588, G8398515457
OpenAlex ID: W4407956740