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Using only independent high-scale OPE input, we investigate QCD sum rule constraints on two currently incompatible versions of the isovector vector spectral function, one obtained from electroproduction (EM) data, the other from hadronic τ decay data. Sum rules involving weighted integrals over the spectral function, from threshold to a variable upper endpoint s0, are employed. It is shown that both the normalization and slope with respect to s0 of the EM spectral integrals disagree with the corresponding OPE expectations, while both normalization and slope are in good agreement when hadronic τ decay data is used instead. These results favor determinations of the leading hadronic vacuum polarization contribution to aμ obtained using the τ decay data, and hence Standard Model predictions for aμ compatible with the current experimental determination.

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Hadronic vacuum polarization contribution to — 2 of the leptons and α(Mz)

Nuclear Physics B - Proceedings Supplements ◽

10.1016/s0920-5632(96)90017-1 ◽

1996 ◽

Vol 51 (3) ◽

pp. 131-141 ◽

Cited By ~ 25

Author(s):

F. Jegerlehner

Keyword(s):

Vacuum Polarization ◽

Polarization Contribution

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The hadronic vacuum polarization contribution to $(g-2)_\mu$ from $2+1$ flavours of O($a$) improved Wilson quarks

10.22323/1.334.0139 ◽

2019 ◽

Cited By ~ 1

Author(s):

Hartmut Wittig ◽

Antoine Gerardin ◽

Tim Harris ◽

Georg von Hippel ◽

Ben Hörz, ◽

...

Keyword(s):

Vacuum Polarization ◽

Polarization Contribution

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Muon g – 2 theory: The hadronic part

EPJ Web of Conferences ◽

10.1051/epjconf/201816600022 ◽

2018 ◽

Vol 166 ◽

pp. 00022 ◽

Cited By ~ 70

Author(s):

Fred Jegerlehner

Keyword(s):

Light Scattering ◽

Energy Range ◽

Lattice Qcd ◽

Vacuum Polarization ◽

Recent Progress ◽

Axial Vector ◽

Status Report ◽

Leading Order ◽

Future Prospects ◽

Polarization Effects

I present a status report of the hadronic vacuum polarization effects for the muon g–2, to be considered as an update of [1]. The update concerns recent new inclusive R measurements from KEDR in the energy range 1.84 to 3.72 GeV. For the leading order contributions I find [see formula in PDF] based on e+e- data [incl. τ data], [see formula in PDF] (NLO) and [see formula in PDF] (NNLO). Collecting recent progress in the hadronic light-by-light scattering I adopt π0, η, η' [95 ± 12] + axial-vector [8 ± 3] + scalar [-6 ± 1] + π, K loops [-20 ± 5] + quark loops [22 ± 4] + tensor [1 ± 0] + NLO [3 ± 2] which yields [see formula in PDF]. With these updates I find [see formula in PDF] a 4.1 σ deviation. Recent lattice QCD results and future prospects to improve hadronic contributions are discussed.

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