b → s transitions in family-dependent U(1)' models

Abstract

We analyze flavor-changing-neutral-current (FCNC) effects in the b s transitions that are induced by family non-universal U(1)′ gauge symmetries. After systematically developing the necessary formalism, we present a correlated analysis for the ΔB = 1,2 processes. We adopt a model-independent approach in which we only require family-universal charges for the first and second generations and small fermion mixing angles. We analyze the constraints on the resulting parameter space from Bs-s mixing and the time-dependent CP asymmetries of the penguin-dominated B d (π,φ,η′,ρ,ω,f0)KS decays. Our results indicate that the currently observed discrepancies in some of these modes with respect to the Standard Model predictions can be consistently accommodated within this general class of models. © SISSA 2009.