Mixing and lifetimes of b‐hadrons.

Abstract

We review the status of mixing and lifetimes of b‐hadrons. We will show that ΔΓ/ΔM, asl and φ are better suited to search for new physics effects than ΔM alone, because of our poor knowledge of the decay constants. The theoretical precision in the determination of Γ12/M12 —which contains all information on ΔΓ/ΔM, asl and φ—can be tested directly by investigating the lifetimes of b‐hadrons, because both quantities rely on the same theoretical footing. In particular we will also present a numerical estimate for the lifetime of the Ξb ‐baryon.