CP violation - a new era

Abstract

This chapter reviews the evidence that supports the Kobayashi-Maskawa picture of CP violation, as well as the various arguments against this picture. The Standard Model predicts that the only way that CP is violated is through the Kobayashi-Maskawa mechanism. Various alternative scenarios of CP violation that have been phenomenologically viable for many years are unambiguously excluded. The experimental result and its implications for theory signify a new era in the study of CP violation. Various CP violating observables can be calculated with very small hadronic uncertainties. One motivation to measure CP violating processes is that almost any extension of the Standard Model provides new sources of CP violation. The SM picture of CP violation is testable because the Kobayashi-Maskawa mechanism is unique and predictive. The strongest argument that new sources of CP violation must exist in Nature comes from baryogenesis.