CP violation and the standard model

Following the observation of parity violation in weak interactions in 1956, the discovery of CP violation in the decay of neutral kaons in 1964 was a great shock. Since then considerable experimental and theoretical work has been devoted to understanding its occurrence and origin, particularly in th e context of the standard model. Recent experimental data have enabled us t o understand the kaon system rather completely, and in conjunction with-dat a from the decays of B masons a meaningful test of the predictions of the s tandard model has been possible. Before reviewing the data and its consiste ncy with theoretical predictions, we explain the origin of CP violation in the standard model, and present the phenomenology of mixing and CP violatio n in the decay of the K-0. Finally, we indicate which experimental results over the next 5-10 years are Likely to have the biggest impact on our under standing of the origin of CP violation.