{
  "annotation_id": "469f2879-dd39-4ba3-912a-167293d26102",
  "date_created": "2026-03-02T18:01:21.826000Z",
  "date_modified": "2026-03-02T18:01:21.826000Z",
  "file_hash": "0d8fc7e92d11df0e0b5f863d2a3e713327439ec860a518f2233b05c930b8c3c3",
  "private": false,
  "record": {
    "abstract": "The positronium molecule (Ps$_2$) has not been experimentally observed yet\nbecause its tiny (4.5 eV) binding energy cannot be detected when the molecule\nannihilates by emitting two photons with energy of 0.51 MeV each. It is shown\nin this paper that the electric dipole transition between the recently found\nL=1 excited-state and the L=0 ground-state with its characteristic photon\nenergy of 4.94 eV is a clear signature of the existence of the positronium\nmolecule and the possibility of its experimental observation is realistic. The\nprobability of this transition is about 17 % of the total decay rate. An other\nCoulomb four-body system containing positron, HPs (the positronium hydride or\nhydrogen positride), is also included for comparison.",
    "arxiv_id": "physics/9804023",
    "authors": [
      "J. Usukura",
      "K. Varga",
      "Y. Suzuki"
    ],
    "categories": [
      "physics.atom-ph",
      "physics.chem-ph"
    ],
    "doi": "10.1103/PhysRevA.58.1918",
    "title": "Signature of the existence of the positronium molecule",
    "url": "https://arxiv.org/abs/physics/9804023"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "239b161e-3f00-4199-951c-cde2ae7f8163",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}