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arXiv · 1211.0828

Leading-order hadronic contributions to a_μ and α_{QED} from N_f=2+1+1 twisted mass fermions

Xu Feng·Grit Hotzel·Karl Jansen·Marcus Petschlies·Dru B. Renner
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Abstract

We present the first four-flavour lattice calculation of the leading-order hadronic vacuum-polarisation contribution to the anomalous magnetic moment of the muon, a_μ^{hvp}, and the hadronic running of the QED coupling constant, Δα_{QED}^{hvp} (Q^2). In the heavy sector a mixed-action setup is employed. The bare quark masses are determined from matching the K- and D-meson masses to their physical values. Several light quark masses are used in order to yield a controlled extrapolation to the physical pion mass by utilising a recently proposed improved method. We demonstrate that this method also works in the four-flavour case.

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Xu Feng, Grit Hotzel, Karl Jansen, Marcus Petschlies, Dru B. Renner. 2012-11-05. Leading-order hadronic contributions to a_μ and α_{QED} from N_f=2+1+1 twisted mass fermions. https://arxiv.org/abs/1211.0828

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