B0d, s– [formula omitted] mass-differences from QCD spectral sum rules

Abstract

We present the first QCD spectral sum rules analysis of the SU(3) breaking parameter ξ and an improved estimate of the renormalization group invariant (RGI) bag constant B B q both entering into the B 0 d, s – B 0 d,s mass-differences. The averages of the results from the Laplace and moment sum rules to order α s are f B B B ≃(247±59) MeV and ξ≡ f B s B B s f B B B ≃(1.18±0.03) , in units where f π =130.7 MeV. Combined with the experimental data on the mass-differences ΔM d, s , one obtains the constraint on the CKM weak mixing angle | V ts / V td | 2⩾20.0(1.1). Alternatively, using the weak mixing angle from the analysis of the unitarity triangle and the data on ΔM d , one predicts ΔM s =18.6(2.2) ps −1 in agreement with the present experimental lower bound and within the reach of Tevatron 2.