{
  "id": "0708.0578",
  "version": "v2",
  "published": "2007-08-03T20:09:33.000Z",
  "updated": "2007-09-29T22:19:42.000Z",
  "title": "Transverse momentum dependence of the angular distribution of the Drell-Yan process",
  "authors": [
    "Edmond L Berger",
    "Jian-Wei Qiu",
    "Ricardo A. Rodriguez-Pedraza"
  ],
  "comment": "18 pages, 4 figures; typos corrected, references updated, a few clarifications recommended by the referee. Paper accepted for publication in Physical Review D",
  "journal": "Phys.Rev.D76:074006,2007",
  "doi": "10.1103/PhysRevD.76.074006",
  "categories": [
    "hep-ph",
    "hep-ex"
  ],
  "abstract": "We calculate the transverse momentum Q_{\\perp} dependence of the helicity structure functions for the hadroproduction of a massive pair of leptons with pair invariant mass Q. These structure functions determine the angular distribution of the leptons in the pair rest frame. Unphysical behavior in the region Q_{\\perp} --> 0 is seen in the results of calculations done at fixed-order in QCD perturbation theory. We use current conservation to demonstrate that the unphysical inverse-power and \\ln(Q/Q_{\\perp}) logarithmic divergences in three of the four independent helicity structure functions share the same origin as the divergent terms in fixed-order calculations of the angular-integrated cross section. We show that the resummation of these divergences to all orders in the strong coupling strength \\alpha_s can be reduced to the solved problem of the resummation of the divergences in the angular-integrated cross section, resulting in well-behaved predictions in the small Q_{\\perp} region. Among other results, we show the resummed part of the helicity structure functions preserves the Lam-Tung relation between the longitudinal and double spin-flip structure functions as a function of Q_{\\perp} to all orders in \\alpha_s.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2007-09-29T22:19:42.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "12.38.Bx",
      "13.85.Qk",
      "12.38.Cy"
    ],
    "keywords": [
      "transverse momentum dependence",
      "angular distribution",
      "drell-yan process",
      "angular-integrated cross section",
      "independent helicity structure functions share"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "APS",
      "journal": "Physical Review D",
      "year": 2007,
      "month": "Oct",
      "volume": 76,
      "number": 7,
      "pages": "074006"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 18,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 757572,
      "adsabs": "2007PhRvD..76g4006B"
    }
  }
}