{
  "annotation_id": "9155a495-df5a-46d9-87a8-b156bebe154d",
  "date_created": "2026-03-02T18:00:05.117000Z",
  "date_modified": "2026-03-02T18:00:05.117000Z",
  "file_hash": "1ee6a7df06ccd98ac096a9d3aa93df8cf55c3a7386d7baef808be06132101ae7",
  "private": false,
  "record": {
    "abstract": "For the effective-range function $k\\cot \\delta $, a pole approximation that\ninvolves a small number of parameters is derived on the basis of the Bargmann\nrepresentation of the $S$ matrix. The parameters of this representation, which\nhave a clear physical meaning, are related to the parameters of the Bargmann\n$S$ matrix by simple equations. By using a polynomial least-squares fit to the\nfunction $k\\cot \\delta $ at low energies, the triplet low-energy parameters of\nneutron-proton scattering are obtained for the latest experimental data of\nArndt et al. on phase shifts. The results are $a_{t}=5.4030 $fm, $r_{t}=1.7494\n$fm, and $v_{2}=0.163 $fm$^{3}$. With allowance for the values found for the\nlow-energy scattering parameters and for the pole parameter, the pole\napproximation of the function $k\\cot \\delta $ provides an excellent description\nof the triplet phase shift for neutron-proton scattering over a wide energy\nrange ($T_{\\text{lab}}\\lesssim 1000 $MeV), substantially improving the\ndescription at low energies as well. For the experimental phase shifts of Arndt\net al., the triplet shape parameters $v_{n}$ of the effective-range expansion\nare obtained by using the pole approximation. The description of the phase\nshift by means of the effective-range expansion featuring values found for the\nlow-energy scattering parameters proves to be fairly accurate over a broad\nenergy region extending to energy values approximately equal to the energy at\nwhich this phase shift changes sign, this being indicative of a high accuracy\nand a considerable value of the effective-range expansion in describing\nexperimental data on nucleon-nucleon scattering. The properties of the deuteron\nthat were calculated by using various approximations of the effective-range\nfunction comply well with their experimental values.",
    "arxiv_id": "nucl-th/0502041",
    "authors": [
      "V. A. Babenko",
      "N. M. Petrov"
    ],
    "categories": [
      "nucl-th"
    ],
    "doi": "10.1134/1.1866377",
    "title": "Description of the two-nucleon system on the basis of the Bargmann   representation of the S matrix",
    "url": "https://arxiv.org/abs/nucl-th/0502041"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "e557abf6-9117-4dd1-80d3-07b50b565970",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}