{
  "annotation_id": "44612cd8-21d4-47b0-83b3-d2c8916c760b",
  "date_created": "2026-03-02T18:00:43.481000Z",
  "date_modified": "2026-03-02T18:00:43.481000Z",
  "file_hash": "eb00afb7c622c86ea33e1011c2464e95cb5507e4b0fd1ef41adac83bf411bff3",
  "private": false,
  "record": {
    "abstract": "A new {\\it ab initio} theoretical formulation to calculate $Z_{eff}$ and\nhence the positron annihilation rates is presented using the on-shell and\nhalf-offshell T-matrix scattering amplitudes without any explicit use of the\nscattering wave function. The formulation is exact and universal, as long as\nthe dynamics of the system can be described by a Lippmann-Schwinger type\nequation. It could serve as an effective tool as all the $T-$, $K-$, and\n$S-$matrix formulations, yield directly the scattering amplitudes; not the wave\nfunction. We also present a basic numerical test of the formulation.",
    "arxiv_id": "physics/0210116",
    "authors": [
      "P K Biswas"
    ],
    "categories": [
      "physics.atom-ph"
    ],
    "title": "A new ab initio method of calculating $Z_{eff}$ and positron   annihilation rates using coupled-channel T-matrix amplitudes",
    "url": "https://arxiv.org/abs/physics/0210116"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "1966cd0f-28ec-49eb-89a9-de3005426dd3",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}