Hadronic contribution to the muon g-2: a Dyson-Schwinger perspective

TL;DR

This paper uses Dyson-Schwinger equations of QCD to calculate hadronic contributions to the muon g-2, achieving good agreement with existing models for vacuum polarization and providing a preliminary estimate for light-by-light scattering.

Contribution

It demonstrates that the Dyson-Schwinger approach can reliably compute hadronic contributions to muon g-2, including vacuum polarization and light-by-light scattering, with competitive accuracy.

Findings

Good agreement with dispersion relation results for HVP

Preliminary LBL value of (217 ± 91) × 10^{-11}

DSE approach shows promise for precise g-2 calculations

Abstract

We summarize our results for hadronic contributions to the anomalous magnetic moment of the muon ($a_\mu$), the one from hadronic vacuum-polarisation (HVP) and the light-by-light scattering contribution (LBL), obtained from the Dyson-Schwinger equations (DSE's) of QCD. In the case of HVP we find good agreement with model independent determinations from dispersion relations for $a_\mu^\mathrm{HVP}$ as well as for the Adler function with deviations well below the ten percent level. From this we conclude that the DSE approach should be capable of describing $a_\mu^\mathrm{LBL}$ with similar accuracy. We also present results for LBL using a resonance expansion of the quark anti-quark T-matrix. Our preliminary value is $a_\mu^\mathrm{LBL}=(217 \pm 91) \times 10^{-11}$.