{
  "id": "1707.04966",
  "version": "v1",
  "published": "2017-07-17T00:23:41.000Z",
  "updated": "2017-07-17T00:23:41.000Z",
  "title": "From hadrons to quarks in neutron stars",
  "authors": [
    "Gordon Baym",
    "Tetsuo Hatsuda",
    "Toru Kojo",
    "Philip D. Powell",
    "Yifan Song",
    "Tatsuyuki Takatsuka"
  ],
  "comment": "36 pages, 33 figures, 3 tables; to be published in Reports on Progress in Physics",
  "categories": [
    "astro-ph.HE",
    "hep-ph",
    "nucl-ex",
    "nucl-th"
  ],
  "abstract": "We review the equation of state of matter in neutron stars from the solid crust through the liquid nuclear matter interior to the quark regime at higher densities. We focus in detail on the question of how quark matter appears in neutron stars, and how it affects the equation of state. After discussing the crust and liquid nuclear matter in the core we briefly review aspects of microscopic quark physics relevant to neutron stars, and quark models of dense matter based on the Nambu- Jona-Lasinio framework, in which gluonic processes are replaced by effective quark interactions. We turn then to describing equations of state useful for interpretation of both electromagnetic and gravitational observations, reviewing the emerging picture of hadron-quark continuity in which hadronic matter turns relatively smoothly, with at most only a weak first order transition, into quark matter with increasing density. We review construction of unified equations of state that interpolate between the reasonably well understood nuclear matter regime at low densities and the quark matter regime at higher densities. The utility of such interpolations is driven by the present inability to calculate the dense matter equation of state in QCD from first principles. As we review, the parameters of effective quark models - which have direct relevance to the more general structure of the QCD phase diagram of dense and hot matter - are constrained by neutron star mass and radii measurements, in particular favoring large repulsive density-density and attractive diquark pairing interactions. Lastly we describe the structure of neutron stars constructed from unified equations of states, and give parametrized forms of the equations of state useful for neutron star modeling.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2017-07-17T00:23:41.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "quark matter",
      "higher densities",
      "understood nuclear matter regime",
      "liquid nuclear matter interior",
      "weak first order transition"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 36,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}