Radiative pion and muon decays in the PEN experiment

Radiative decays of the muon, μ⁺  -> e⁺ + ν_e + ν^bar_μ + γ, and pion, π⁺ -> e⁺ + ν_e + γ, or π_e2γ, where the photon carries away a non-negligible portion of the available energy, are sensitive in different ways to departures from the basic V-A dynamics of the weak interaction.  Like other pion and muon decay channels, they are described with extreme precision in the standard model (SM) of elementary particles and fields.  Hence, both processes are effective in studies of the limits on certain non-SM interactions.  Additionally, the radiative pion electronic decay offers a direct the weak form factors of the pion.  The ratio of the axial-vector and vector pion form factors, F_A/F_V is one of the basic inputs in low energy chiral lagrangians, such as chiral perturbation theory.  We discuss the progress on the analysis of pion and muon radiative decays in the PEN experiment.