{
  "annotation_id": "3665e8f5-8e6a-4eb5-84b5-623190781535",
  "date_created": "2026-03-02T18:00:18.669000Z",
  "date_modified": "2026-03-02T18:00:18.669000Z",
  "file_hash": "1dda5af6be831032d73c3a89c3e3d1022793dc2739edc24d71f96b76f78ad992",
  "private": false,
  "record": {
    "abstract": "We show that the contact couplings of neutral pseudoscalar and axial mesons\nto the nucleon are proportional to $\\Delta s$, the fraction of nucleon spin\ncarried by the strange quark sea, and thus are strongly suppressed relative to\nthe couplings of charged mesons to the nucleon. On the other side, recent high\naccuracy data on $\\eta $ photoproduction at threshold reveal the need for\nnon--negligibile $\\eta NN$ vertices, while fitting $\\bar N N$ phase shifts by\nmeans of effective meson exchange potentials requires a substantial presence of\n$f_1$ mesons there. We here advocate the idea to attribute the couplings of\nneutral pseudoscalar and axial vector mesons to effective triangular diagrams\ncontainig non--strange mesons and demonstrate its usefulness in describing\navailable data.",
    "arxiv_id": "nucl-th/9609021",
    "authors": [
      "M. Kirchbach",
      "L. Tiator",
      "S. Neumeier",
      "S. Kamalov"
    ],
    "categories": [
      "nucl-th"
    ],
    "title": "New Insights into the Coupling of $\\eta $ and $f_1$ Mesons to the   Nucleon",
    "url": "https://arxiv.org/abs/nucl-th/9609021"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "47109143-8021-4469-ab69-918f1e4762f3",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}