ABSTRACT
This chapter describes the phenomenology of weak interactions, introducing two topics which have been the focus of intense experimental effort in the recent decade: CP violation in B meson decays, and oscillations in both neutral meson and neutrino systems. It also describes the gauge theory theme, with the Glasow-Salam-Weinberg electroweak theory. Although the formalism is similar, the phenomenology of CP violation in neutral K-meson decays is very different from that in neutral B-meson decays. In the K case, CP violation is a very small effect, typically at the level of parts per thousand or smaller; its observation by Cristenson et al. was a historic achievement. But the neutral K system is most simply (and traditionally) approached by starting with the assumption that CP is conserved.
