The dimuon CP asymmetry, mixing & General Minimal Flavor Violation

The DØ Collaboration reported a 3.2 σ deviation from the standard model prediction in the like-sign dimuon asymmetry. Assuming that new physics contributes only to Bd,s mixing, we study the general implications of the measurement, and then in the context of the general minimal flavor violation (GMFV) framework. We find that this framework gives a good fit to the data. Universal new physics with similar contributions relative to the SM in the Bd and Bs systems are possible, but the data favor a larger deviation in Bs than in Bd mixing. We also briefly discuss the GMFV contributions to CP violation in mixing.