The anomalous magnetic moment if the muon is an observable that receives quantum corrections from all three interactions of the Standard Model. The experimental and theoretical determinations seem to disagree thus opening the possibility to look for new physics beyond the Standard Model. The deviation is, however, only marginally larger than the uncertainties for both experiment and theory. On the theoretical side the uncertainty is dominated by contributions from the strong interactions. Therefore we consider the two most relevant hadronic contributions to the muon anomaly. In particular we calculate the hadronic vacuum polarisation (HVP) and the hadronic light-by-light(HLBL) scattering diagrams using the method of Dyson-Schwinger equations. We show that we reproduce HVP on the less-ten-percent level compared to model independent determinations. Our ongoing efforts for the much more complicated HLBL contribution show that the existing model calculations have underestimated their error. In particular we find that Green´s function that have a realistic momentum dependence and tensor structure have to be taken into account for such a calculations. We explain and exemplify why we think that the Dyson-Schwinger approach is able to achieve a HLBL prediction that is on a similar level of accuracy as the HVP result that we present.
Verknüpfung zu Publikationen oder weiteren Datensätzen
