{
  "id": "1407.2781",
  "version": "v2",
  "published": "2014-07-10T13:33:59.000Z",
  "updated": "2014-12-01T19:45:26.000Z",
  "title": "A heuristic description of high-pT hadron production in heavy ion collisions",
  "authors": [
    "Jan Nemchik",
    "Roman Pasechnik",
    "Irina Potashnikova"
  ],
  "comment": "14 pages, 17 figures; extra clarifications added in Sects. II and III (with additional Figs. 1-6) and in the extended Sect. V B (with additional Fig.11), references added, conclusions unchanged",
  "categories": [
    "hep-ph",
    "hep-ex",
    "nucl-th"
  ],
  "abstract": "Using a simplified model for in-medium dipole evolution accounting for color filtering effects we study production of hadrons at large transverse momenta $p_T$ in heavy ion collisions. In the framework of this model, several important sources of the nuclear suppression observed recently at RHIC and LHC have been analysed. A short production length of the leading hadron $l_p$ causes a strong onset of color transparency effects manifested themselves as a steep rise of the nuclear modification factor $R_{AA}(p_T)$ at large hadron $p_T$'s. A dominance of quarks with higher $l_p$ leads to a weaker suppression at RHIC than the one observed at LHC. In the RHIC kinematic region we include an additional suppression factor steeply falling with $p_T$, which is tightly related to the energy conservation constraints. The latter is irrelevant at LHC up to $p_T\\lesssim 70$ GeV while it causes a rather flat $p_T$ dependence of the $R_{AA}(p_T)$ factor at RHIC c.m. energy $\\sqrt{s} = 200$ GeV and even an increasing suppression with $p_T$ at $\\sqrt{s} = 62$ GeV. The calculations contain only a medium density adjustment, and for an initial time scale $t_0$ = 1 fm we found the energy-dependent maximal values of the transport coefficient, $\\hat{q}_0 = 0.7, 1.0$ and 1.3 GeV$^2$/fm corresponding to $\\sqrt{s} = 62, 200$ GeV and 2.76 TeV, respectively. We present a broad variety of predictions for the nuclear modification factor and the azimuthal asymmetry which are in a good agreement with available data from experiments at RHIC and LHC.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2014-07-10T13:33:59.000Z",
      "abstract": "Using a simplified model for in-medium dipole evolution accounting for color filtering effects we study production of hadrons at large transverse momenta $p_T$ in heavy ion collisions. In the framework of this model, several important sources of the nuclear suppression observed recently at RHIC and LHC have been analysed. A short production length of the leading hadron $l_p$ causes a strong onset of the color transparency effects manifested themselves as a steep rise of the nuclear modification factor $R_{AA}(p_T)$ at large hadron $p_T$'s. A dominance of quarks with higher $l_p$ leads to a weaker suppression at RHIC than the one observed at LHC. In the RHIC kinematic region we include an additional suppression factor steeply falling with $p_T$, which is tightly related to the energy conservation constraints. The latter is irrelevant at LHC up to $p_T\\lesssim 70$ GeV while it causes a rather flat $p_T$ dependence of the $R_{AA}(p_T)$ factor at RHIC c.m. energy $\\sqrt{s} = 200$ GeV and even an increasing suppression with $p_T$ at $\\sqrt{s} = 62$ GeV. The calculations contain only a medium density adjustment, and for an initial time scale $t_0$ = 1 fm we found the energy-dependent maximal values of the transport coefficient, $\\hat{q}_0 = 0.7, 1.0$ and $1.3$ GeV$^2/$fm corresponding to $\\sqrt{s} = 62, 200$ GeV and $2.76$ TeV, respectively. We present a broad variety of predictions for the nuclear modification factor and the azimuthal asymmetry which are in a good agreement with available data from experiments at RHIC and LHC.",
      "comment": "9 pages, 10 figures. arXiv admin note: text overlap with arXiv:1208.4951",
      "journal": null,
      "doi": null
    },
    {
      "version": "v2",
      "updated": "2014-12-01T19:45:26.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "heavy ion collisions",
      "high-pt hadron production",
      "heuristic description",
      "nuclear modification factor",
      "suppression factor steeply falling"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1140/epjc/s10052-015-3319-7",
      "journal": "European Physical Journal C",
      "year": 2015,
      "month": "Feb",
      "volume": 75,
      "pages": 95
    },
    "note": {
      "typesetting": "TeX",
      "pages": 14,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 1305622,
      "adsabs": "2015EPJC...75...95N"
    }
  }
}