We study the large branching ratios of B→ηK* decays and the time-dependent CP asymmetry SϕKS anomaly of B→ϕKS decay in a flavor changing Z′ model associated with flavor changing neutral currents at the tree level. Considering the right-handed flavor changing couplings and setting ξLL = ξRL = ξLR = ξRR = ξ, we obtain 0.011 < ξ < 0.0131, this parameter region could give a simultaneous explanation to these anomalies of B→ηK* and B→ϕKS decays. The results are consistent with the constraints and the assumptions of some references.
Tree-level flavor-changing neutral currents in theBsystem: FromCPasymmetries to rare decays