{"paper":{"title":"Parts-per-million-accurate determination of the K${\\alpha}$ photoionization resonance of Be-like oxygen with resolution of its $^{16}$O-$^{18}$O isotopic shift","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["astro-ph.HE","astro-ph.IM","physics.plasm-ph"],"primary_cat":"physics.atom-ph","authors_text":"Awad Mohamed, Chintan Shah, Dominic Hache, Fabrizio Nicastro, Filipe Grilo, Jonas Danisch, Joschka Goes, Jos\\'e R. Crespo L\\'opez-Urrutia, Marc Botz, Marcello Coreno, Monica de Simone, Moto Togawa, Pedro Amaro, Roberta Totani, Stefano Orlando, Steffen K\\\"uhn, Thomas Pfeifer, Vladimir A. Yerokhin","submitted_at":"2026-07-01T14:32:46Z","abstract_excerpt":"We determine with high accuracy the energy of the inner-shell transition $1s^2 2s^2~{}^1\\mathrm{S}_0 \\rightarrow 1s~2s^2~2p_{3/2}~{}^1\\mathrm{P}_1$ ${}^{16}\\mathrm{O}_{K\\alpha}^{4+}$ at $554.372(3)~\\mathrm{eV}$ ($\\lambda$ = $22.36480(12)~\\unicode{x212B}$) as well as its small shift of $2.2 \\pm 1.3~\\mathrm{meV}$ ($\\Delta \\lambda$ = $0.089(52)~\\mathrm{m}\\unicode{x212B}$) for the ${}^{18}\\mathrm{O}$ isotope. This transition blends with a $K_\\alpha$ line of $\\mathrm{O}^{5+}$ used in astrophysical diagnostics, potentially affecting its reliability. In contrast to our experimental uncertainty of $\\p"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2607.00996","kind":"arxiv","version":1},"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/2607.00996/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"}