scholarly journals Review of recent Leading-Order Hadronic Vacuum Polarization calculation

2014 ◽  
Author(s):  
Zhiqing Philippe Zhang
Keyword(s):  
Vacuum Polarization ◽  
Leading Order ◽  
Polarization Calculation

scholarly journals Muon g – 2 theory: The hadronic part

2018 ◽  
Vol 166 ◽  
pp. 00022 ◽  
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.

scholarly journals Vacuum Polarization with Zero-Range Potentials on a Hyperplane

Universe ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 92
Author(s):  
Davide Fermi
Keyword(s):  
Vacuum Polarization ◽  
Minkowski Spacetime ◽  
Local Version ◽  
Quantum Vacuum ◽  
Leading Order ◽  
Vacuum Fluctuations ◽  
Regularization Technique ◽  
Dirac Delta ◽  
Zero Range ◽  
Dirac Delta Potential

The quantum vacuum fluctuations of a neutral scalar field induced by background zero-range potentials concentrated on a flat hyperplane of co-dimension 1 in (d+1)-dimensional Minkowski spacetime are investigated. Perfectly reflecting and semitransparent surfaces are both taken into account, making reference to the most general local, homogeneous and isotropic boundary conditions compatible with the unitarity of the quantum field theory. The renormalized vacuum polarization is computed for both zero and non-zero mass of the field, implementing a local version of the zeta regularization technique. The asymptotic behaviors of the vacuum polarization for small and large distances from the hyperplane are determined to leading order. It is shown that boundary divergences are softened in the specific case of a pure Dirac delta potential.

HADRONIC τ AND e+e-SPECTRA, CONTRIBUTION TO (g-2)μAND QCD STUDIES

2013 ◽  
Vol 28 (25) ◽  
pp. 1360011 ◽  
Author(s):  
BOGDAN MALAESCU
Keyword(s):  
Experimental Data ◽  
Theoretical Prediction ◽  
Vacuum Polarization ◽  
Leading Order ◽  
Dominant Contribution ◽  
Spectral Functions ◽  
Hadronic Contribution

The dominant contribution to the uncertainty of the theoretical prediction of the (g-2) of the muon comes from the leading order hadronic vacuum polarization part. This contribution is evaluated using either tau or e+e-experimental data. The same experimental data are exploited for QCD studies. We present an update of the ALEPH hadronic spectral functions. This update induces only small changes for the hadronic contribution to the (g-2) of the muon and for the QCD fits. We also present updates of the contributions to g-2 for several channels of e+e-into hadrons.

scholarly journals Lattice QCD results for the HVP contribution to the anomalous magnetic moments of leptons

2018 ◽  
Vol 175 ◽  
pp. 06016
Author(s):  
◽  
Szabolcs Borsanyi ◽  
Zoltan Fodor ◽  
Taichi Kawanai ◽  
Stefan Krieg ◽  
...  
Keyword(s):  
Lattice Qcd ◽  
Lattice Spacing ◽  
Vacuum Polarization ◽  
Magnetic Moments ◽  
Leading Order ◽  
Order Contribution ◽  
Systematic Uncertainties ◽  
Linear Extent ◽  
Charged Leptons

We present lattice QCD results by the Budapest-Marseille-Wuppertal (BMW) Collaboration for the leading-order contribution of the hadron vacuum polarization (LOHVP) to the anomalous magnetic moments of all charged leptons. Calculations are performed with u, d, s and c quarks at their physical masses, in volumes of linear extent larger than 6 fm, and at six values of the lattice spacing, allowing for controlled continuum extrapolations. All connected and disconnected contributions are calculated for not only the muon but also the electron and tau anomalous magnetic moments. Systematic uncertainties are thoroughly discussed and comparisons with other calculations and phenomenological estimates are made.

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