{
  "annotation_id": "e566f323-1fc3-45a1-8eb1-b7f230c2531b",
  "date_created": "2026-03-02T18:00:28.092000Z",
  "date_modified": "2026-03-02T18:00:28.092000Z",
  "file_hash": "45aa5e1332f2ccee68c406ec8eac8f683651515af6903f557a65b684c8001bec",
  "private": false,
  "record": {
    "abstract": "We investigate the structure of the nucleon resonance N^*(1440) (Roper)\nwithin a coupled-channel meson exchange model for pion-nucleon scattering. The\ncoupling to pipiN states is realized effectively by the coupling to the sigmaN,\npiDelta and rhoN channels. The interaction within and between these channels is\nderived from an effective Lagrangian based on a chirally symmetric Lagrangian,\nwhich is supplemented by well known terms for the coupling of the Delta isobar,\nthe omega meson and the \u0027sigma\u0027, which is the name given here to the strong\ncorrelation of two pions in the scalar-isoscalar channel. In this model the\nRoper resonance can be described by meson-baryon dynamics alone; no genuine\nN^*(1440) (3 quark) resonance is needed in order to fit piN phase shifts and\ninelasticities.",
    "arxiv_id": "nucl-th/9911080",
    "authors": [
      "O. Krehl",
      "C. Hanhart",
      "S. Krewald",
      "J. Speth"
    ],
    "categories": [
      "nucl-th"
    ],
    "doi": "10.1103/PhysRevC.62.025207",
    "journal_ref": "Phys.Rev. C62 (2000) 025207",
    "title": "What is the structure of the Roper resonance?",
    "url": "https://arxiv.org/abs/nucl-th/9911080"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "c87d0191-2a2f-472b-b735-8d1479e271e5",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}