{"paper":{"title":"Search for $K_L \\!\\to\\! \\pi^0 \\nu \\overline{\\nu}$ and $K_L \\!\\to\\! \\pi^0 X^0$ Decays at the J-PARC KOTO Experiment","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"hep-ex","authors_text":"A. S. Kurilin, B. Beckford, C. Lin, D. Mcfarland, D. Naito, E. J. Kim, G. Y. Lim, H. Haraguchi, H. Nanjo, H. Nishimiya, H. Okuno, H. Schamis, H. Watanabe, H. Y. Yoshida, I. Kamiji, J. Beechert, J. Comfort, J. K. Woo, J. L. Kim, J. Ma, J. Micallef, J. W. Ko, J. W. Lee, K. Bryant, K. Dona, K. Kotera, K. Miyazaki, K. Nakagiri, KOTO Collaboration: J. K. Ahn, K. Sato, K. Shiomi, M. Campbell, M. Hutcheson, M. Ohsugi, M. Sasaki, M. Taylor, M. Tecchio, M. Togawa, N. Hara, N. Kawasaki, N. McNeal, N. Sasao, N. Shimizu, Q. Lin, R. Murayama, S. H. Chen, S. Seki, S. Shinohara, S. Su, S. Suzuki, T. Inagaki, T. K. Komatsubara, T. Mari, T. Masuda, T. Matsumura, T. Nomura, T. Sato, T. Shimogawa, T. Shinkawa, T. Yamanaka, Y. B. Hsiung, Y. C. Tung, Y. J. Kim, Y. Luo, Y. Maeda, Y. Sato, Y. Sugiyama, Y. Tajima, Y. W. Wah","submitted_at":"2018-10-23T04:48:49Z","abstract_excerpt":"A search for the rare decay $K_L \\!\\to\\! \\pi^0 \\nu \\overline{\\nu}$ was performed. With the data collected in 2015, corresponding to $2.2 \\times 10^{19}$ protons on target, a single event sensitivity of $( 1.30 \\pm 0.01_{\\rm stat} \\pm 0.14_{\\rm syst} ) \\times 10^{-9}$ was achieved and no candidate events were observed. We set an upper limit of $3.0 \\times 10^{-9}$ for the branching fraction of $K_L \\!\\to\\! \\pi^0 \\nu \\overline{\\nu}$ at the 90% confidence level (C.L.), which improved the previous limit by almost an order of magnitude. An upper limit for $K_L \\!\\to\\! \\pi^0 X^0$ was also set as $2."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1810.09655","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"}