Speaker
Description
During the last few years we have developed the theoretical framework for including radiative corrections to lattice computations of the $\pi_{\ell 2}$ and $K_{\ell 2}$ leptonic decay rates and performed the corresponding numerical calculations. This necessarily includes the treatment of infrared divergences. In this talk we discuss the extension of this framework to semileptonic decays, such as $K_{\ell 3}$ decays. We show that the $1/L$ finite-volume corrections in the QED_L formulation of lattice QED are universal but depend on the derivatives of the QCD form-factors with respect to the square of the momentum transfer $q^2$. We also discuss the consequences of the presence of intermediate states which have energies which are smaller than those of the external states.
