{
  "annotation_id": "04ab7f5e-f663-4a48-a184-cd38b061a694",
  "date_created": "2026-03-02T18:00:21.108000Z",
  "date_modified": "2026-03-02T18:00:21.108000Z",
  "file_hash": "20eb91cb43d78325950ac13cb5a05dc6cee5ae9d7bcac881a7593ba4bc652147",
  "private": false,
  "record": {
    "abstract": "We study the nuclear (or A) dependence of the coherent eta photoproduction\nreaction in a relativistic impulse approximation approach. We use a standard\nrelativistic parameterization of the elementary amplitude, based on a set of\nfour Lorentz- and gauge-invariant amplitudes, to calculate the coherent\nproduction cross section from He-4, C-12, and Ca-40. In contrast to\nnonrelativistic treatments, our approach maintains the full relativistic\nstructure of the process. The nuclear structure affects the process through the\nground-state tensor density. This density is sensitive to relativistic effects\nand depends on A in a different manner than the vector density used in\nnonrelativistic approaches. This peculiar dependence results in He-4 having a\ncross section significantly smaller than that of C-12---in contrast to existent\nnonrelativistic calculations. Distortion effects are incorporated through an\neta-nucleus optical potential that is computed in a simple ``t rho\u0027\u0027\napproximation.",
    "arxiv_id": "nucl-th/9710005",
    "authors": [
      "L. J. Abu-Raddad",
      "J. Piekarewicz",
      "A. J. Sarty",
      "M. Benmerrouche"
    ],
    "categories": [
      "nucl-th"
    ],
    "doi": "10.1103/PhysRevC.57.2053",
    "journal_ref": "Phys.Rev.C57:2053-2056,1998",
    "title": "Nuclear dependence of the coherent eta photoproduction reaction in a   relativistic approach",
    "url": "https://arxiv.org/abs/nucl-th/9710005"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "2fa27580-1ce3-4aeb-b4f7-ab66f7a58a4e",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}