2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/47727Theoretical aspects of kaon and muon decays are reviewed. In particular, three topics on kaon and muon decays, namely $K \to πν\barν$ processes, T violation in $K^+ \to π^0μ^+ ν$ decay and lepton flavor violation in muon decay are considered. Theoretical backgrounds and possible significance on new physics searches by these processes are discussed.10 pages, 2 figures, talk given at International KEK Workshop on Kaon, Muon, Neutrino Physics and Future, Oct.31 - Nov. 1, 1997, KEKHigh Energy Physics - Phenomenologytext