Constraint of B⁰_d,s - B̄⁰ _d,s mixing on warped extra-dimension model

Recent CDF measurement of the B⁰_s - ⁰ _s oscillation frequency at the Tevatron imposes significant constraint on various models for new physics. A warped extra-dimension model with custodial isospin symmetry accommodates the B⁰_d,s - ⁰_d,s mixing at tree level mainly through the Kaluza-Klein gluons. This is due to the misalignment between the bulk gauge eigenstates and the localized Yukawa eigenstates of the bulk fermions. We adopt the universal 5D Yukawa coupling model where all Yukawa couplings are of order one. The SM fermion mass spectra and mixings are controlled by the bulk Dirac mass parameters. With two versions of the hadronic parameter values for _Bd,sf²_Bd,s, we investigate the implication of the observed B⁰_d,s - ⁰_d,s mixings on this model. The CP-violating effects on the B_d system is shown to provide very strong constraint: The first Kaluza-Klein mass of a gluon (M _KK) has its lower bound about 3.7 TeV with 1σ uncertainty.