New physics in CP violation experiments

CP violation plays a privileged role in our quest for new physics beyond the electroweak standard model. In the standard model, the violation of CP in the weak interactions has a single source: the phase of the quark mixing matrix (the CKM matrix, for Cabibbo-Kobayashi-Maskawa). Most extensions of the standard model exhibit new sources of CP violation. For instance, the truly minimal supersymmetric extension of the standard model has two new phases in addition to the CKM phase. Given that CP violation is so tiny in the kaon system, is still largely unexplored in B physics, and is negligibly small in the electric dipole moments, it is clear that new physics may have a good chance to manifest some departure from the standard model in this particularly challenging class of rare phenomena. On the other hand, it is also apparent that CP violation generally represents a major constraint on any attempt at model building beyond the standard model. In this review, we tackle these two sides of t...