Radiative corrections to the decays K_L^0->e^+e^- and K_L^0->mu^+mu^-

Abstract

We calculate the rates and lepton (l) invariant mass distributions for decays of the form 0^{-+}->l^+l^-\gamma, which are important radiative corrections to the purely leptonic decays 0^{-+}->l^+l^-. Our approach uses the loop diagrams which arise by including the two photon intermediate state and we retain the imaginary parts of the loops - a radiative extension of the `unitarity bound' for the process. These results are compared which those obtained using a model in which the meson couples directly to the leptons.