{
  "annotation_id": "c41417f2-4099-4b57-9f57-d2bd115f14f7",
  "date_created": "2026-03-02T18:00:46.850000Z",
  "date_modified": "2026-03-02T18:00:46.850000Z",
  "file_hash": "9e7373a9d8c3f9e63296a029888f6c0d72b0764d6db0fbe10c5eec9fa510069e",
  "private": false,
  "record": {
    "abstract": "This is a late answer to question #79 by R.I. Khrapko, \"Does plane wave not\ncarry a spin?,\" Am. J. Phys. /69/, 405 (2001), and a complement (on gauge\ninvariance, massive spin 1 and 1/2, and massless spin 2 fields) to the paper by\nH.C. Ohanian, \"What is spin?,\" Am. J. Phys. /54/, 500--505 (1985). In\nparticular, it is confirmed that \"spin\" is a classical quantity which can be\ncalculated for any field using its definition, namely that it is just the\nnon-local part of the conserved angular momentum. This leads to explicit\nexpressions which are bilinear in the fields and which agree with their\nstandard \"quantum\" counterparts.",
    "arxiv_id": "physics/0308027",
    "authors": [
      "Andre Gsponer"
    ],
    "categories": [
      "physics.class-ph"
    ],
    "title": "What is spin?",
    "url": "https://arxiv.org/abs/physics/0308027"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "20b34e25-01f0-4112-91ec-b47fafd76bb0",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}