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arXiv · 1412.6934

Study of the Couplings of QED and QCD from the Adler Function

Anthony Francis·Gregorio Herdoíza·Hanno Horch·Benjamin Jäger·Harvey B. Meyer·Hartmut Wittig
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Abstract

The contribution from hadronic vacuum polarisation effects is responsible for a large fraction of the theoretical uncertainty in the running of the QED coupling. The current level of uncertainty has become a limitation for electroweak precision tests. We use lattice QCD simulations with two flavours of O$(a)$ improved Wilson fermions to determine the Adler function in a broad range of the momentum transfer $Q^2$. The running of the QED coupling, including valence contributions from $u$, $d$, $s$ and $c$ quarks, is compared to phenomenological results at intermediate $Q^2$ values. In the large $Q^2$ regime, the lattice determination of the Adler function is fitted to perturbation theory in order to examine the feasibility of a determination of the strong coupling constant.

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Anthony Francis, Gregorio Herdoíza, Hanno Horch, Benjamin Jäger, Harvey B. Meyer, Hartmut Wittig. 2014-12-22. Study of the Couplings of QED and QCD from the Adler Function. https://arxiv.org/abs/1412.6934

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