{
  "annotation_id": "9a2e2319-4acf-45ac-a958-e7d13b981981",
  "date_created": "2026-03-02T18:00:11.983000Z",
  "date_modified": "2026-03-02T18:00:11.983000Z",
  "file_hash": "55153acc1c9e1f1db4ee10fccaea46030720f8d2d98af0a050eb2453011e6156",
  "private": false,
  "record": {
    "abstract": "The presence of two photon exchange in $ep$ elastic scattering and in the\ncrossed processes ($\\bar p +p\\leftrightarrow \\ell^+ +\\ell^-$, $\\ell=e$ or\n$\\mu$) is discussed in terms of three complex amplitudes which are functions of\ntwo kinematical variables, the momentum transfer squared $q^2$ and the\npolarization of the virtual photon, $\\epsilon$. Model independent expressions\nof the differential cross section and of polarization observables are derived.\nParticular attention is devoted to the extraction of hadron electromagnetic\nform factors which becomes much more difficult in presence of two photon\nexchange, and to the relevant experimental observables which could give\nevidence for such mechanism.",
    "arxiv_id": "nucl-th/0611053",
    "authors": [
      "E. Tomasi-Gustafsson"
    ],
    "categories": [
      "nucl-th"
    ],
    "title": "Model Independent Considerations on Two-Photon Exchange in Electron   Proton Scattering and in the Crossed Processes",
    "url": "https://arxiv.org/abs/nucl-th/0611053"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "cb18eeed-7b50-4fd4-8671-aedffdafd854",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}