Speaker
Norman Christ
(Columbia University)
Description
We discuss the counter terms needed to renormalize our recent $K\to\mu^+\mu^-$ decay calculation (Phys.Rev.D 113 (2026) 7, 074523). Three different classes of divergent sub-diagrams are identified and the steps needed to renormalize them described. The relation between these classes and the five distinct types of quark contractions is described in terms of an expansion in powers of $\alpha_s$ evaluated at the energy scale of the charm quark mass.