© 2015 Elsevier B.V. Starting from the dispersion relation for the I=1 vector polarization, we employ hadronic τ decay data to construct a highly physical model of the subtracted polarization and use this to investigate, and quantify, systematic issues in existing lattice determinations of the leading-order hadronic vacuum polarization contribution to the muon anomalous magnetic moment. The model is also used to demonstrate that a hybrid strategy, involving direct numerical integration of lattice data for Euclidean Q2 above ~0.1-0.2GeV2 and the use of three possible reliable low-Q2 representations to cover the region below this, serves to reduce the errors induced by the identified systematic problems to the sub-percent level, making the hybrid approach an attractive option for use in future lattice analyses.
- Lattice QCD
- Muon anomalous magnetic moment
- τ decay data