Pion and Kaon box contribution to $a_{\mu}^{\text{HLbL}}$

Understand

We present an evaluation of the $\pi^\pm$ and $K^\pm$ box contributions to the hadronic light-by-light piece of the muon's anomalous magnetic moment, $a_\mu$.

• The calculation of the corresponding electromagnetic form factors (EFFs) is performed within a Dyson-Schwinger equations (DSE) approach to quantum chromodynamics.
• These form factors are calculated in the so-called rainbow-ladder (RL) truncation, following two different evaluation methods and, subsequently, in a further improved approximation scheme which incorporates meson cloud effects.
• The results are mutually consistent, indicating that in the domain of relevance for $a_\mu$ the obtained EFFs are practically equivalent.