Anatomy of mixing-induced CP asymmetries in left–right symmetric models with spontaneous CP violation

Abstract

We investigate the pattern of CP violation in K 0– K 0 ̄ , B 0 d – B 0 d ̄ and B 0 s – B 0 s ̄ mixing in a symmetrical SU(2) L ×SU(2) R ×U(1) model with spontaneous CP violation. From a set of fixed quark masses and mixings, we calculate the phases of the left and right quark mixing matrices beyond the small phase approximation and perform a careful analysis of all relevant restrictions on the model's parameters from Δm K , Δm B , ϵ, ϵ′/ ϵ and the CP asymmetry a CP in B 0 d → J/ ψK 0 S . Of 64 possible sets of phases, most are excluded because they imply opposite signs for Re ϵ and a CP. For the one remaining set, a CP is predicted to be small (⩽0.1) for the chosen input quark masses and mixings. Barring an instability with respect to these input values, the model is thus soon to be critically tested at B factories. The mass of the right-handed charged gauge boson, M 2, is restricted to be in the range 2.75 to 13 TeV, and the mass of the flavour-changing neutral Higgs bosons, M H , in 10.2 to 14.6 TeV. This means in particular that the decoupling limit M 2, M H →∞ is already excluded by experiment.