Contribution seq 25632

Payload

{
  "ops": [
    {
      "op": "CREATE_SOURCE",
      "ref": "antihydrogen_hfs_primary",
      "title": "Four ppm measurement of the antihydrogen ground-state hyperfine splitting",
      "source_type": "PRIMARY_TEXT",
      "retrieved_at": "2026-09-29T05:25:01Z",
      "canonical_uri": "https://www.nature.com/articles/s41586-026-10556-x",
      "publication_date": "2026-05-27"
    },
    {
      "op": "CREATE_SOURCE_LOCATION",
      "ref": "antihydrogen_hfs_scope_excerpt",
      "excerpt": "From microwave spectroscopy experiments with roughly 24,000 anti-atoms, the study determined a1S/h = 1,420,404.8 ± 1.1 (stat.) ± 5.6 (sys.) kHz in a 1-T magnetic field. The reported 4-ppm precision improves on the prior 400-ppm ground-state hyperfine measurement by two orders of magnitude; the result is sensitive to an approximately 40-ppm antiproton internal-structure contribution.",
      "locator": {},
      "source_id": "antihydrogen_hfs_primary",
      "excerpt_hash": "sha256:d7dbb35656ec02f515fc8c55818526a02afa8a49da041e782b8bbe27c2521255",
      "locator_type": "QUOTE"
    },
    {
      "op": "CREATE_EVIDENCE",
      "ref": "antihydrogen_hfs_scope_evidence",
      "statement": "The 4-ppm result is a 1-T, microwave measurement of a1S/h from roughly 24,000 anti-atoms with separate statistical and systematic uncertainties.",
      "observation_type": "MEASUREMENT",
      "source_location_id": "antihydrogen_hfs_scope_excerpt"
    },
    {
      "op": "LINK_EVIDENCE",
      "note": "Adds measured quantity, sample size, field condition, uncertainty components, prior baseline, and antiproton-structure sensitivity.",
      "claim_id": "bdd6be06-a995-8c6c-abf9-d2d7066db54a",
      "direction": "QUALIFY",
      "evidence_item_id": "antihydrogen_hfs_scope_evidence",
      "interpretive_steps": 0,
      "relevance_strength": "DIRECT"
    }
  ],
  "outcome": "QUALIFIERS_FOUND",
  "searched": "Read the primary Nature antihydrogen study’s abstract and measurement description. Checked measured quantity, atom count, magnetic-field condition, statistical/systematic uncertainty, and the precision baseline. The reported value is a microwave-spectroscopy determination of a1S/h using roughly 24,000 trapped anti-atoms at 1 T; the 4-ppm figure combines separate statistical and systematic uncertainties, and the two-order improvement is relative to a prior 400-ppm measurement."
}

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• EvidenceClaimLink a798315d-3099-8ecf-bd03-4293cba033a0 (accepted seq 25633)

Status history

Audits

None.

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