{
  "annotation_id": "99bdfa10-f8ca-4220-9e2e-1f3111814107",
  "date_created": "2026-03-02T18:01:03.421000Z",
  "date_modified": "2026-03-02T18:01:03.421000Z",
  "file_hash": "bf097685ec1614e8baca70f01a2c2ff109a3b2f6ea712adde6a6f5af6e419ba3",
  "private": false,
  "record": {
    "abstract": "We report precise measurements of ground-state, $\\lambda$-doublet microwave\ntransitions in the hydroxyl radical molecule (OH). Utilizing slow, cold\nmolecules produced by a Stark decelerator we have improved over the precision\nof the previous best measurement by twenty-five-fold for the F\u0027 = 2 $\\to$ F = 2\ntransition, yielding (1 667 358 996 $\\pm$ 4) Hz, and by ten-fold for the F\u0027 = 1\n$\\to$ F = 1 transition, yielding (1 665 401 803 $\\pm$ 12) Hz. Comparing these\nlaboratory frequencies to those from OH megamasers in interstellar space will\nallow a sensitivity of 1 ppm for $\\Delta\\alpha/\\alpha$ over $\\sim$$10^{10}$\nyears.",
    "arxiv_id": "physics/0601054",
    "authors": [
      "Eric R. Hudson",
      "H. J. Lewandowski",
      "Brian C. Sawyer",
      "Jun Ye"
    ],
    "categories": [
      "physics.atom-ph",
      "physics.gen-ph"
    ],
    "doi": "10.1103/PhysRevLett.96.143004",
    "title": "Cold Molecule Spectroscopy for Constraining the Evolution of the Fine   Structure Constant",
    "url": "https://arxiv.org/abs/physics/0601054"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "c9f424f2-1021-4d21-b38a-031817c28c2b",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}