{"paper":{"title":"A new search for the $K_{L} \\to \\pi^0 \\nu \\overline{\\nu}$ and $K_{L} \\to \\pi^{0} X^{0}$ decays","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"hep-ex","authors_text":"A. S. Kurilin, B. Beckford, B. Brubaker, C. Carruth, C. Lin, D. Mcfarland, D. Naito, E. Iwai, E. J. Kim, G. H. Lee, G. Takahashi, G. Y. Lim, H. Haraguchi, H. Nanjo, H. Okuno, H. S. Lee, H. Watanabe, H. Yamauchi, H. Yokota, H. Yoshimoto, H. Y. Yoshida, I. Kamiji, I. Teo, J. Comfort, J. K. Ahn, J. K. Woo, J. Ma, J. Micallef, J. S. Son, J. Stevens, J. W. Ko, J. W. Lee, J. Xu, K. Miyazaki, K. Morgan, K. Nakagiri, K. Sato, K. Shiomi, K. Y. Baek, M. Campbell, M. Hutcheson, M. Isoe, M. Sasaki, M. Tecchio, M. Togawa, M. Yamaga, N. Kawasaki, N. Sasao, N. Whallon, R. Murayama, R. Ogata, S. Banno, S. Chu, S. H. Chen, S. K. Lee, S. Seki, S. Shinohara, S. Su, S. Suzuki, S. Yamamoto, T. Cai, T. Furukawa, T. Hineno, T. Inagaki, T. Kamibayashi, T. K. Komatsubara, T. Masuda, T. Matsumura, T. Nomura, T. Ota, T. Sato, T. Shimogawa, T. Shinkawa, T. Toyoda, T. Usuki, T. Yamanaka, Y. B. Hsiung, Y. C. Tung, Y. D. Ri, Y. J. Kim, Y. Maeda, Y. Nakajima, Y. Nakaya, Y. Odani, Y. Sugiyama, Y. Tajima, Y. Takashima, Y. T. Duh, Y. W. Wah, Y. Yanagida","submitted_at":"2016-09-12T23:58:27Z","abstract_excerpt":"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/$c^{2}$."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1609.03637","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}