{
  "id": "0903.3385",
  "version": "v1",
  "published": "2009-03-19T18:16:57.000Z",
  "updated": "2009-03-19T18:16:57.000Z",
  "title": "Limit on the diffuse flux of ultra-high energy tau neutrinos with the surface detector of the Pierre Auger Observatory",
  "authors": [
    "The Pierre Auger Collaboration"
  ],
  "comment": "19 pages, 9 figures",
  "journal": "Phys.Rev.D79:102001,2009",
  "doi": "10.1103/PhysRevD.79.102001",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "Data collected at the Pierre Auger Observatory are used to establish an upper limit on the diffuse flux of tau neutrinos in the cosmic radiation. Earth-skimming $\\nu_{\\tau}$ may interact in the Earth's crust and produce a $\\tau$ lepton by means of charged-current interactions. The $\\tau$ lepton may emerge from the Earth and decay in the atmosphere to produce a nearly horizontal shower with a typical signature, a persistent electromagnetic component even at very large atmospheric depths. The search procedure to select events induced by $\\tau$ decays against the background of normal showers induced by cosmic rays is described. The method used to compute the exposure for a detector continuously growing with time is detailed. Systematic uncertainties in the exposure from the detector, the analysis and the involved physics are discussed. No $\\tau$ neutrino candidates have been found. For neutrinos in the energy range $2\\times10^{17}$ eV $< E_{\\nu}$ $<$ $2\\times10^{19}$ eV, assuming a diffuse spectrum of the form $E_{\\nu}^{-2}$, data collected between 1 January 2004 and 30 April 2008 yield a 90% confidence-level upper limit of $E_\\nu^{2} \\mathrm{d}N_{\\nu_\\tau}/\\mathrm{d}E_{\\nu} < 9 \\times 10^{-8}$ GeV cm$^{-2}$ s$^{-1}$ sr$^{-1}$.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2009-03-19T18:16:57.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "98.70.Sa",
      "95.55.Vj",
      "95.85.Ry"
    ],
    "keywords": [
      "ultra-high energy tau neutrinos",
      "pierre auger observatory",
      "diffuse flux",
      "surface detector",
      "upper limit"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "APS",
      "journal": "Physical Review D",
      "year": 2009,
      "month": "May",
      "volume": 79,
      "number": 10,
      "pages": 102001
    },
    "note": {
      "typesetting": "TeX",
      "pages": 19,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 815819,
      "adsabs": "2009PhRvD..79j2001A"
    }
  }
}