Kaon-box contribution to the anomalous magnetic moment of the muon

We present results for the charged kaon-box contributions to the hadronic light-by-light (HLBL) correction of the muon's anomalous magnetic moment. To this end we determine the kaon electromagnetic form factor within the functional approach to QCD using Dyson-Schwinger and Bethe-Salpeter equations and evaluate the kaon-box contribution as defined in the dispersive approach to HLBL. As an update to previous work we also reevaluate the charged pion-box contribution taking effects due to isospin breaking into account. Our results are a(mu)(pi +/--box) = -15.7(2)(3) x 10(-11) and a(mu)(k +/--box) = -0.48(2)(4) x 10(-11) thus confirming the large suppression of box contributions beyond the leading pion box.