Alternative Theories of CP violation

Abstract

Recent improvements to the limit of Delta M_{B_s} imply that pure superweak theories, while not excluded, no longer provide a good fit to the data. A class of general superweak theories is introduced in which all flavor changing interactions are governed by an approximate flavor symmetry which gives a ``3 mechanism''. These theories are in good agreement with data, and predict low values for |V_{td}|, |V_{ub}/V_{cb}|, B(K^+ to pi^+ nu nubar), epsilon'/epsilon and CP asymmetries in B decays, and high values for Delta M_{B_s} and f_B sqrt{B_B}. An important example of such a theory is provided by weak scale supersymmetric theories with soft CP violation. The CP violation originates in the squark mass matrix, and, with phases of order unity, flavor symmetries can yield a correct prediction for the order of magnitude of epsilon_K.