Theoretical status of Bs-mixing and lifetimes of heavy hadrons

Abstract

We review the theoretical status of the lifetime ratios τ B + /τB d , τB s /τB d , τΛ b /τB d and τB c and of the mixing quantities ∆Ms, ∆Γs and φs. ∆Ms and ∆Γs suffer from large uncertainties due to the badly known decay constants, while the ratio ∆Γs/∆Ms can be determined with almost no non-perturbative uncertainties, therefore it can be used perfectly to find possible new physics contributions in the mixing parameters. We suggest a very clear method of visualizing the bounds on new physics and demonstrate this by combining the latest experimental numbers on the mixing quantities quantities with theory-one already gets some hints for new physics contributions, but more precise experimental numbers are needed to draw some definite conclusions. We conclude with a ranking list of all the discussed quantities according to their current theoretical uncertainties and point out possible improvements.

How large can the branching ratio ofBs→τ+τ−be?

“…In Fig. 3 [7,37].) The figure shows that there are values of the couplings that can be consistent with the J/ψφ data as well as the dimuon asymmetry data to within 2σ.…”

CP parameters of the B systems from Tevatron

“…The mixing phase β s with the SM prediction β SM s = arg(−(V ts V * tb )/(V cs V * cb )) ≈ 0.02 measured in decays B s → J/ψφ is also related to the phase φ s (see note in [3]). In paper [4] the notation φ s = −2β s is used, but to distinguish this phase from the CP phase φ s defined above in equation 4 the notation φ J/ψφ s = −2β J/ψφ s as in [5] is preferable.…”

Selected topics in heavy flavour physics

“…(2.14), see e.g. the "note added" in [186,187]. Finally we would like to briefly discuss direct CP violation in hadronic D-meson decays -see [28] and references therein for a more detailed discussion.…”