{
  "id": "1207.5300",
  "version": "v2",
  "published": "2012-07-23T05:51:21.000Z",
  "updated": "2012-09-11T19:46:50.000Z",
  "title": "Dressed-quarks and the nucleon's axial charge",
  "authors": [
    "Lei Chang",
    "Craig D. Roberts",
    "Sebastian M. Schmidt"
  ],
  "comment": "10 pages, 3 figures",
  "categories": [
    "nucl-th",
    "hep-lat",
    "hep-ph",
    "nucl-ex"
  ],
  "abstract": "The nucleon's axial charge, g_A, expresses features that are both fundamental to the strong interaction and crucial to its connection with weak interaction physics. We show that dynamical chiral symmetry breaking (DCSB) suppresses the axial-charge of a dressed-quark, g_A^q, at infrared momenta. Since this effect disappears as chiral symmetry is restored, one may argue that g_A vanishes with the restoration of chiral symmetry because no nucleon bound-state survives the associated transition. The suppression of g_A^q is shown to be part of an explanation for a 25% reduction of g_A from its nonrelativistic quark-model value. Critical too, however, is the presence of dressed-quark angular momentum within the nucleon. The value of g_A^q depends on the kernels of the gap and Bethe-Salpeter equations. We find that incorporation of essentially nonperturbative effects associated with DCSB into these kernels inflates the value relative to that obtained at leading-order in a widely used truncation of QCD's Dyson-Schwinger equations. Such corrections also affect the nucleon's axial radius. In both cases, however, agreement with experiment will require similar improvements to the Faddeev kernel and associated interaction current.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2012-09-11T19:46:50.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "12.38.Lg",
      "12.38.Aw",
      "12.15.-y",
      "14.20.Dh"
    ],
    "keywords": [
      "nucleons axial charge",
      "chiral symmetry",
      "nonrelativistic quark-model value",
      "weak interaction physics",
      "nucleon bound-state survives"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1103/PhysRevC.87.015203",
      "journal": "Physical Review C",
      "year": 2013,
      "month": "Jan",
      "volume": 87,
      "number": 1,
      "pages": "015203"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 10,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 1123511,
      "adsabs": "2013PhRvC..87a5203C"
    }
  }
}