Tests of hadronic vacuum polarization fits for the muon anomalous magnetic moment

Abstract

Using experimental spectral data for hadronic tau decays from the OPAL experiment, supplemented by a phenomenologically successful parameterization for the high-s region not covered by the data, we construct a physically constrained model of the isospin-one vector-channel polarization function. Having such a model as a function of Euclidean momentum Q^2 allows us to explore the systematic error associated with fits to the Q^2 dependence of lattice data for the hadronic electromagnetic current polarization function which have been used in attempts to compute the leading order hadronic contribution, a_μ^HLO, to the muon anomalous magnetic moment. In contrast to recent claims made in the literature, we find that a final error in this quantity of the order of a few percent does not appear possible with current lattice data, given the present lack of precision in the determination of the vacuum polarization at low Q^2. We also find that fits to the vacuum polarization using fit functions based on Vector Meson Dominance are unreliable, in that the fit error on a_μ^HLO is typically much smaller than the difference between the value obtained from the fit and the exact model value. The use of a sequence of Pade approximants known to converge to the true vacuum polarization appears to represent a more promising approach.

17 pages, 4 figures

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Cited by in corpus (18)

• The hadronic vacuum polarization contribution to the muon $g-2$ from lattice QCD
• Lattice simulations with eight flavors of domain wall fermions in SU(3) gauge theory
• Finite-volume effects in the muon anomalous magnetic moment on the lattice
• A New Strategy for the Lattice Evaluation of the Leading Order Hadronic Contribution to $(g-2{)}_{\mu }$
• The hadronic vacuum polarization with twisted boundary conditions
• Lattice calculation of the leading strange quark-connected contribution to the muon $g-2$
• Hadronic vacuum polarization function within dispersive approach to QCD
• Chiral extrapolation of the leading hadronic contribution to the muon anomalous magnetic moment
• A ChPT estimate of the strong-isospin-breaking contribution to the anomalous magnetic moment of the muon
• Leading-order hadronic contributions to the electron and tau anomalous magnetic moments
• Lattice QCD Studies of the Leading Order Hadronic Contribution to the Muon $g-2$
• Hadronic contributions to electroweak observables within DPT
• Leading-order hadronic contributions to the lepton anomalous magnetic moments from the lattice
• Finite-volume effects in the hadronic vacuum polarization
• Vector correlator and scale determination in lattice QCD
• Explaining muon $g-2$ anomaly in a non-universal $U(1{)}_X$ extended SUSY theory
• Towards the physical point hadronic vacuum polarisation from Moebius DWF
• Neutrino mass and charged lepton flavor violation in an extended left-right symmetric model