{
  "annotation_id": "c1789eae-35d7-4ecc-9028-91e7b4103950",
  "date_created": "2026-03-02T18:00:22.043000Z",
  "date_modified": "2026-03-02T18:00:22.043000Z",
  "file_hash": "25c9ad1a55a2edce33e0de479b7ac23f663f6c7c405a9e7fb4269ba48f448199",
  "private": false,
  "record": {
    "abstract": "Electromagnetic properties of off-shell particles are discussed on the basis\nof a purely electromagnetic reaction: virtual Compton scattering off a proton.\nIt is shown that the definition of off-shell electromagnetic form factors is\nnot gauge invariant and that these cannot be investigated in practice. Using\nonly fundamental requirements of gauge invariance it is demonstrated that\noff-shell effects are cancelled in the longitudinal components of the total\nconserved current by the minimal contact current, while the off-shellness\nappears only in the the transverse (gauge invariant) non-pole part. This\nprovides the possibility to introduce an on-shell extrapolated form factor\nF_1^+(q^2) in a gauge invariant way for the unphysical time-like region,\n4m_e^2\u003cq^2, 4M_N^2.",
    "arxiv_id": "nucl-th/9803007",
    "authors": [
      "S. I. Nagorny",
      "A. E. L. Dieperink"
    ],
    "categories": [
      "nucl-th"
    ],
    "title": "Electromagnetic properties of off-shell particles and gauge invariance",
    "url": "https://arxiv.org/abs/nucl-th/9803007"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "fc26e52e-740c-41e1-916f-59b687af03d3",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}