{
  "annotation_id": "3e996866-d7f0-4fa7-88c9-d63f338c0524",
  "date_created": "2026-03-02T18:02:30.809000Z",
  "date_modified": "2026-03-02T18:02:30.809000Z",
  "file_hash": "26596bb5133551fca33ea5c7f446f20fadf80b56aa379e2ccb339975e27ec57f",
  "private": false,
  "record": {
    "abstract": "We consider the excitation dynamics of the two-photon \\sts transition in a\nbeam of atomic hydrogen by 243 nm laser radiation. Specifically, we study the\nimpact of ionization damping on the transition line shape, caused by the\npossibility of ionization of the 2S level by the same laser field. Using a\nMonte-Carlo simulation, we calculate the line shape of the \\sts transition for\nthe experimental geometry used in the two latest absolute frequency\nmeasurements (M. Niering {\\it et al.}, PRL 84, 5496 (2000) and M. Fischer {\\it\net al.}, PRL 92, 230802 (2004)). The calculated line shift and line width are\nin excellent agreement with the experimentally observed values. From this\ncomparison we can verify the values of the dynamic Stark shift coefficient for\nthe \\sts transition for the first time on a level of 15%. We show that the\nionization modifies the velocity distribution of the metastable atoms, the line\nshape of the \\sts transition, and has an influence on the derivation of its\nabsolute frequency.",
    "arxiv_id": "quant-ph/0609114",
    "authors": [
      "N. Kolachevsky",
      "M. Haas",
      "U. D. Jentschura",
      "M. Herrmann",
      "P. Fendel",
      "M. Fischer",
      "R. Holzwarth",
      "Th. Udem",
      "C. H. Keitel",
      "T. W. Haensch"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.74.052504",
    "journal_ref": "Phys. Rev. A 74, 052504 (2006)",
    "title": "Photoionization Broadening of the 1S-2S Transition in a Beam of Atomic   Hydrogen",
    "url": "https://arxiv.org/abs/quant-ph/0609114"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "4efa5b5f-0e08-44ef-b0ff-e5c06dd02de2",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}