CP Violating Lepton Asymmetries from B Decays and Their Implication for Supersymmetric Flavor Models

The lepton and dilepton charge asymmetries from $B_{d}$ and $B_{s}$ are predicted to be small in the standard model, whereas new physics could increase their values significantly. In this paper, we explore the use of the lepton asymmetries as a probe of the flavor structure of supersymmetric theories. In particular, we determine the sensitivity to parameters of various models. We find that in many interesting models which attempt to address the supersymmetric flavor problem, the mixing structure is such that it could be possible to detect new physics. The predictions are model dependent; with a measurement in both the $B_s$ and $B_d$ systems one can hope to constrain the flavor physics model, especially once squarks are detected and their masses measured. Thus, lepton charge asymmetries can be used as an alternative means of searching for new physics and distinguishing among potential solutions to the flavor problem. They are interesting precisely because they are small in the standard model and are therefore necessarily evidence of new physics.