Leading hadronic contribution to the muon magnetic moment from lattice QCD

Abstract

We compute the leading order hadronic vacuum polarization (LO-HVP) contribution to the anomalous magnetic moment of the muon, $(g_{\hat{I}}¼-2)$, using lattice QCD. Calculations are performed with four flavors of 4-stout-improved staggered quarks, at physical quark masses and at six values of the lattice spacing down to 0.064~fm. All strong isospin breaking and electromagnetic effects are accounted for to leading order. The infinite-volume limit is taken thanks to simulations performed in volumes of sizes up to 11~fm. Our result for the LO-HVP contribution to $(g_{\hat{I}}¼-2)$ has a total uncertainty of 0.8\%. Compared to the result of the dispersive approach for this contribution, ours significantly reduces the tension between the standard model prediction for $(g_{\hat{I}}¼-2)$ and its measurement.

Accepted for publication. 116 pages, 34 figures with main, methods and supplementary information. v2: added finite time extent corrections, analyzed new configurations and included suggestions from the community (regarding the continuum limit, scale setting and running of the fine structure constant). v3: revised analysis to take into account referees' comments. Original conclusions unchanged