How to elucidate the mechanism of CP violation.

Abstract

Several CP-violating observables, particularly in semileptonic decays of K's, have the property that they are expected to vanish in the standard model, but are nonzero in alternative models. Thus, they provide very clean ways to test whether the standard model is the (sole) source of CP violation and to determine the properties of any other source that may enter. We mainly consider the transverse muon polarization from ${K}_{\ensuremath{\mu}3}$ (which isolates S and P effective Lagrangians), and the ${K}_{e4}$ spectrum (which contains a term that isolates V and A effective Lagrangians). We briefly comment on ${W}^{\ifmmode\pm\else\textpm\fi{}}$ production, and heavy-quark and -lepton decays.