Lifetimes and oscillations of heavy mesons

Abstract

We review the theoretical status of the lifetime ratios $τ_{B^+} / τ_{B_d}$ and $τ_{B_s} / τ_{B_d}$ and of the mixing quantities $ΔM_s$, $ΔΓ_s$ and $ϕ_s$. We show that the ratio $ΔΓ_s / ΔM_s$ can be determined with almost no non-perturbative uncertainties. Finally we explain how this precise determination of the standard model values can be used to find possible new physics contributions in $ΔM_s $, $ΔΓ_s$, $ΔΓ_s / ΔM_s$ and $a_{fs}^s$. Combining the latest experimental bounds on these quantities one already gets some hints for new physics contributions.