{"paper":{"title":"Direct Measurement of the $5s5p\\,{}^1P_1 \\to 5s4d\\,{}^1D_2$ Decay Rate in Strontium","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"physics.atom-ph","authors_text":"Naohiro Okamoto, Takatoshi Aoki, Yoshio Torii","submitted_at":"2025-10-25T06:32:46Z","abstract_excerpt":"We report the first direct experimental determination of the branching ratio of the $5s4d\\,{}^1D_2 \\to 5s5p\\,{}^3P_2$ transition and the decay rate of the $5s5p\\,{}^1P_1 \\to 5s4d\\,{}^1D_2$ transition in neutral strontium. For more than four decades, these quantities lacked an experimental determination independent of theoretical input. We measure the branching ratio to be $0.177(4)$, significantly lower than the widely cited theoretical value of $0.322$ [C. W. Bauschlicher Jr. {\\it et al.}, J. Phys. B \\textbf{18}, 1523 (1985)]. We also determine the decay rate to be $5.3(5)\\times10^3\\,\\mathrm{"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2510.22184","kind":"arxiv","version":3},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2510.22184/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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"}