Weak mass mixing, CP violation, and the decay of b-quark mesons

Ellis, Gaillard, Nanopoulos, and Rudaz' were first to point out the possibility of large CP-violating effects in neutral B systems. Since the interpretation of the Y as bb, theprospectof observing weak mass mixing and CP violation in B„-B„decay has motivated several estimates of mixing and charge-asymmetry parameters, in the frameworks of both the Kobayashi-Maskawa (KM) model and Higgs exchange. Small predictions from these earlier estimates, especially in the context of the KM model, are not supported by the present work, which allows for larger effects. Substantive methodological improvements over previous analyses contribute to these new findings. Section II presents an extension of the familiar mixing and CP formulas from kaon physics to accommodate the larger CP violation characteristic of B mesons. The unjustified use of an approximation for the CP impurity parameter ~ valid near the origin is thereby avoided. In Sec. III, &1"~, is calculated directly from the absorptive part of the 2W' exchange box chagrams, eliminating large errors from momentum mismatch in analyses based on decay channels. Section IV contains a reevaluation of the KM angles, based on precise expressions for kaon mixing. Section V summarizes B'-B' mixing and charge asymmetry with conclusions regarding their experimental detection. Details of the rarer B,-B, decay are contained in an appendix.