{
  "id": "hep-ph/9812370",
  "version": "v2",
  "published": "1998-12-15T15:32:58.000Z",
  "updated": "1998-12-17T10:01:31.000Z",
  "title": "Evaluation of $α(M_{\\rm Z}^2)$ and $(g-2)_μ$",
  "authors": [
    "Michel Davier"
  ],
  "comment": "13 pages",
  "journal": "Nucl.Phys.Proc.Suppl. 76 (1999) 327-338",
  "doi": "10.1016/S0920-5632(99)00486-7",
  "categories": [
    "hep-ph"
  ],
  "abstract": "This talk summarizes the recent developments in the evaluation of the leading order hadronic contributions to the running of the QED fine structure constant $\\alpha(s)$, at $s=M_{\\rm Z}^2$, and to the anomalous magnetic moment of the muon $(g-2)_\\mu$. The accuracy of the theoretical prediction of these observables is limited by the uncertainties on the hadronic contributions. Significant improvement has been achieved in a series of new analyses which is presented historically in three steps: (I), use of $\\tau$ spectral functions in addition to $e^+e^-$ cross sections, (II), extended use of perturbative QCD and (III), application of QCD sum rule techniques. The most precise values obtained are: $\\Delta\\alpha_{\\rm had}(M_{\\rm Z}^2)$, $=(276.3\\pm1.6)\\times10^{-4}$, yielding $\\alpha^{-1}(M_{\\rm Z}^2)=128.933\\pm0.021$, and $a_\\mu^{\\rm had}=(692.4\\pm6.2)\\times 10^{-10}$ with which one finds for the complete Standard Model prediction $a_\\mu^{\\rm SM}=(11 659 159.6\\pm6.7)\\times10^{-10}$. For the electron $(g-2)_e$, the hadronic contribution is $a_e^{\\rm had}=(187.5\\pm1.8)\\times 10^{-14}$.",
  "revisions": [
    {
      "version": "v2",
      "updated": "1998-12-17T10:01:31.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "evaluation",
      "complete standard model prediction",
      "qcd sum rule techniques",
      "leading order hadronic contributions",
      "qed fine structure constant"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 13,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 480952
    }
  }
}