{"paper":{"title":"Sweeping the pion chimney for axion-like particles with KOTO","license":"http://creativecommons.org/licenses/by/4.0/","headline":"KOTO data on six-photon kaon decays can set new limits on axion-like particles with masses near the neutral pion.","cross_cats":[],"primary_cat":"hep-ph","authors_text":"Christiane Scherb, Dean J. Robinson, Reuven Balkin, Stefania Gori","submitted_at":"2025-08-11T18:51:37Z","abstract_excerpt":"We demonstrate that novel limits on prompt axion-like particles (ALPs) in the hard-to-probe mass range near the neutral pion - the so-called pion chimney - may be obtained from recasting $K_L \\to 3\\pi^0 \\to 6\\gamma$ KOTO data to search for $K_L \\to 2\\pi^0 a \\to 6\\gamma$. We also explore the power of KOTO $6\\gamma$ data to probe $K_L \\to 2\\pi^0a$ for a broader range of ALP masses, incorporating displaced decays."},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"Novel limits on prompt axion-like particles (ALPs) in the hard-to-probe mass range near the neutral pion may be obtained from recasting K_L to 3 pi^0 to 6 gamma KOTO data to search for K_L to 2 pi^0 a to 6 gamma.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The background from standard-model KL to 3 pi^0 decays can be controlled or subtracted sufficiently well in the six-photon final state, and the detector acceptance and reconstruction efficiency for the ALP signal are comparable to the background process so that meaningful limits can be extracted.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Recasting KOTO KL to 3pi0 to 6gamma data yields novel limits on prompt ALPs near the pion mass via KL to 2pi0 a to 6gamma, with extensions to displaced decays for wider ALP masses.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"KOTO data on six-photon kaon decays can set new limits on axion-like particles with masses near the neutral pion.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"f53400ba9a46b854994b6ce811c198715baa3baca217c6cb59014f4af133b6fc"},"source":{"id":"2508.08402","kind":"arxiv","version":1},"verdict":{"id":"59eac67f-095b-4abe-bb79-930e7179f0e2","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-18T23:19:46.692008Z","strongest_claim":"Novel limits on prompt axion-like particles (ALPs) in the hard-to-probe mass range near the neutral pion may be obtained from recasting K_L to 3 pi^0 to 6 gamma KOTO data to search for K_L to 2 pi^0 a to 6 gamma.","one_line_summary":"Recasting KOTO KL to 3pi0 to 6gamma data yields novel limits on prompt ALPs near the pion mass via KL to 2pi0 a to 6gamma, with extensions to displaced decays for wider ALP masses.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The background from standard-model KL to 3 pi^0 decays can be controlled or subtracted sufficiently well in the six-photon final state, and the detector acceptance and reconstruction efficiency for the ALP signal are comparable to the background process so that meaningful limits can be extracted.","pith_extraction_headline":"KOTO data on six-photon kaon decays can set new limits on axion-like particles with masses near the neutral pion."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2508.08402/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":14,"sample":[{"doi":"","year":2008,"title":"Final Results from the KTeV Experiment on the Decay KL -> pi0 gamma gamma","work_id":"1faead35-a09c-4e28-a569-79bdeb17ca6a","ref_index":1,"cited_arxiv_id":"0805.0031","is_internal_anchor":true},{"doi":"","year":2005,"title":"S. Gori, G. Perez, and K. Tobioka, KOTO vs. NA62 Dark Scalar Searches, JHEP 08, 110, arXiv:2005.05170 [hep- ph]","work_id":"9f00db1e-2ffd-4b87-ac39-8546d9e62c8c","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2019,"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","work_id":"f3e1e55b-8356-49df-a25e-9aea4e6fdf5b","ref_index":3,"cited_arxiv_id":"1810.09655","is_internal_anchor":true},{"doi":"","year":2023,"title":"C. Lin et al. (KOTO), Search for the Pair Production of Dark Particles X with KL0 →XX, X→γγ, Phys. Rev. Lett. 130, 111801 (2023), arXiv:2209.11019 [hep-ex]","work_id":"73788d88-3f31-4e36-be33-a2135c1637ce","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2025,"title":"Probing CP and flavor violation in neutral kaon decays with ALPs","work_id":"2b540ea8-e616-45c6-86e1-e5c172c98f16","ref_index":5,"cited_arxiv_id":"2507.01947","is_internal_anchor":true}],"resolved_work":14,"snapshot_sha256":"b5a4af3402b579923d089f87f3905af357a5811e28b92be355c018d1f4c1b867","internal_anchors":6},"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"}