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arXiv · 0705.3802

Theoretical status of $B_s$-mixing and lifetimes of heavy hadrons

Alexander Lenz
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Abstract

We review the theoretical status of the lifetime ratios $τ_{B^+} / τ_{B_d}$, $τ_{B_s} / τ_{B_d}$, $τ_{Λ_b} / τ_{B_d}$ and $τ_{B_c}$ and of the mixing quantities $ΔM_s$, $ΔΓ_s$ and $ϕ_s$. $ΔM_s$ and $ΔΓ_s$ suffer from large uncertainties due to the badly known decay constants, while the ratio $ΔΓ_s / ΔM_s$ 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.

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Alexander Lenz. 2012-07-01. Theoretical status of $B_s$-mixing and lifetimes of heavy hadrons. https://doi.org/10.1016/j.nuclphysbps.2007.11.089

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