{
  "annotation_id": "7f4a74da-6278-45cc-8f3c-8ef15fc14ad8",
  "date_created": "2026-03-02T18:00:04.663000Z",
  "date_modified": "2026-03-02T18:00:04.663000Z",
  "file_hash": "eb344b2c33e09a7e761755aae2dca0181e715381858a2e42a7171a02e13ff961",
  "private": false,
  "record": {
    "abstract": "The stiffness of the hadronic equation of state has been extracted from the\nproduction rate of $K^+$ mesons in heavy ion collisions around 1 $A$ GeV\nincident energy. The data are best described with a compressibility coefficient\n$\\kappa$ around 200 MeV, a value which is usually called ``soft\u0027\u0027. This is\nconcluded from a detailed comparison of the results of transport theories with\nthe experimental data using two different procedures: (i) the energy dependence\nof the ratio of $K^+$ from Au+Au and C+C collisions and (ii) the centrality\ndependence of the $K^+$ multiplicities. It is demonstrated that input\nquantities of these transport theories which are not precisely known, like the\nkaon-nucleon potential, the $\\Delta N \\to N K^+ \\Lambda$ cross section or the\nlife time of the $\\Delta$ in matter do not modify this conclusion.",
    "arxiv_id": "nucl-th/0506087",
    "authors": [
      "Ch. Hartnack",
      "H. Oeschler",
      "Joerg Aichelin"
    ],
    "categories": [
      "nucl-th"
    ],
    "doi": "10.1103/PhysRevLett.96.012302",
    "journal_ref": "Phys.Rev.Lett.96:012302,2006",
    "title": "Hadronic Matter is Soft",
    "url": "https://arxiv.org/abs/nucl-th/0506087"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "b52a6f0c-3ac1-460e-9398-bdec1e5a9670",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}