{
  "annotation_id": "35498233-532c-4aff-9c07-c87624a07abd",
  "date_created": "2026-03-02T18:00:17.871000Z",
  "date_modified": "2026-03-02T18:00:17.871000Z",
  "file_hash": "b8d44329b0cf15a6b53fa0472df71b0b81591a1ae72b40b2bd4537c548108d9f",
  "private": false,
  "record": {
    "abstract": "An exactly solvable model suitable for the description of single and\ndouble-beta decay processes of the Fermi-type is introduced. The model is\nequivalent to the exact shell-model treatment of protons and neutrons in a\nsingle j-shell. Exact eigenvalues and eigenvectors are compared to those\ncorresponding to the hamiltonian in the quasiparticle basis (qp) and with the\nresults of both the standard quasiparticle random phase approximation (QRPA)\nand the renormalized one (RQRPA). The role of the scattering term of the\nquasiparticle hamiltonian is analyzed. The presence of an exact eigenstate with\nzero energy is shown to be related to the collapse of the QRPA. The RQRPA and\nthe qp solutions do not include this zero-energy eigenvalue in their spectra,\nprobably due to spurious correlations. The meaning of this result in terms of\nsymmetries is presented.",
    "arxiv_id": "nucl-th/9612034",
    "authors": [
      "Jorge G. Hirsch",
      "Peter O. Hess",
      "Osvaldo Civitarese"
    ],
    "categories": [
      "nucl-th"
    ],
    "doi": "10.1103/PhysRevC.56.199",
    "journal_ref": "Phys.Rev.C56:199-211,1997",
    "title": "Single- and double-beta decay Fermi-transitions in an exactly solvable   model",
    "url": "https://arxiv.org/abs/nucl-th/9612034"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "e2080995-e051-44a2-911a-f226794d0307",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}