Pion, muon decays and weak interaction symmetries

Abstract

We review the recent measurements of the rare pion decays: Pi+ -> Pi0 e+ Nu [pion beta, Pi_(e3), or Pi_beta decay], radiative decay Pi+ -> e+ Nu Gamma [Pi_(e2Gamma) or RPD], and Pi+ -> e+ Nu [Pi_(e2)] decay, as well as the radiative muon decay, Mu -> e Nu Nu-bar Gamma, their theoretical implications, and prospects for further improvement.Comment: 4 pages, 2 figures; talk presented at the Fourth International Symposium on Symmetries in Subatomic Physics (SSP 2009), held at the National Taiwan University, Taipei, Taiwan, 2-5 June 2009; to appear in "Symmetries in Subatomic Physics", P. Hwang, ed., North Holland