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Hadronic vacuum polarization effects in alpha_{em}(M_Z)

F. Jegerlehner
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Abstract

Recent evaluations of the hadronic vacuum polarization contributions to the effective fine-structure constant alpha_{em}(M_Z) are summarized and commented. A new update based on corrected CMD-2 data is presented. My new estimates are Delta alpha_{had}^{(5)}(M_Z) = 0.027773 +/- 0.000354 (e^+e^- - data based) and Delta alpha_{had}^{(5)}(M_Z) = 0.027664 +/- 0.000173 (via the Adler-function and extended use of pQCD). Prospects of further possible progress is discussed.

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F. Jegerlehner. 2003-08-11. Hadronic vacuum polarization effects in alpha_{em}(M_Z). https://arxiv.org/abs/hep-ph/0308117

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