The Theoretical status of $\bar{B}-B$-mixing and lifetimes of heavy hadrons

Abstract

In this talk we review the theoretical status of the lifetime ratios of heavy hadrons and of the B-mixing quantities $\Delta M_s$, $\Delta {\Gamma }_s$ and ${\varphi }_s$. While $\Delta M_s$ and $\Delta {\Gamma }_s$ suffer from large uncertainties due to the badly known decay constants, the ratio $\Delta {\Gamma }_s/\Delta M_s$ can be determined with almost no non-perturbative uncertainties, therefore it can be used to look for possible new physics effects.

Comments: Invited Plenary talk at The 4th International Conference on Flavor Physics, Sep. 24-28, 2007, Beijing