{
  "id": "hep-ph/0401246",
  "version": "v1",
  "published": "2004-01-30T16:08:15.000Z",
  "updated": "2004-01-30T16:08:15.000Z",
  "title": "Inclusive $J/ψ$ Productions at $e^+ e^-$ Colliders",
  "authors": [
    "K. Hagiwara",
    "E. Kou",
    "Z. -H. Lin",
    "C. -F. Qiao",
    "G. -H. Zhu"
  ],
  "comment": "25 pages with 8 figures",
  "journal": "Phys.Rev.D70:034013,2004",
  "doi": "10.1103/PhysRevD.70.034013",
  "categories": [
    "hep-ph"
  ],
  "abstract": "Inclusive $J/\\psi$ productions in $e^+ e^-$ annihilation is studied in the framework of NRQCD. We first review the leading-order calculations of the cross sections for $e^+ e^- \\to J/\\psi c \\bar{c}$ and $e^+ e^- \\to J/\\psi g g$ and find that their ratio is about 1:1.5 at $\\sqrt{s}\\simeq 10$\\gev. This result is in conflict with the current measurements by the Belle Collaboration, which finds that the process $e^+e^- \\to J/\\psi c\\bar{c}$ accounts for about 2/3 of all the prompt $J/\\psi$'s. We show that the discrepancy in the total rate as well as in the $J/\\psi$ momentum distributions can be resolved by considering a large renormalization $K$ factor ($K\\simeq 4$) for the $J/\\psi c \\bar {c}$ cross section and by taking into account collinear suppression in the end-point energy region of $J/\\psi g g$ production. Detailed studies of the model predictions in terms of the density matrix are performed and various momentum and angular distributions are presented as functions of the $K$ factors. These distributions can be used to determine the normalizations of each subprocess provided that the production and decay angular distributions do not alter much by higher order corrections.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2004-01-30T16:08:15.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "13.60.Le",
      "14.40.Lb",
      "12.38.Bx",
      "12.39.Jh"
    ],
    "keywords": [
      "production",
      "cross section",
      "higher order corrections",
      "decay angular distributions",
      "end-point energy region"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "APS",
      "journal": "Phys. Rev. D"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 25,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 643637
    }
  }
}