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تسجيل مستخدم جديدTheoretical status of $B_s$-mixing and lifetimes of heavy hadrons
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Alexander Lenz
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We review the theoretical status of the lifetime ratios $tau_{B^+} / tau_{B_d}$, $tau_{B_s} / tau_{B_d}$, $tau_{Lambda_b} / tau_{B_d}$ and $tau_{B_c}$ and of the mixing quantities $Delta M_s$, $Delta Gamma_s$ and $phi_s$. $Delta M_s$ and $Delta Gamma_s$ suffer from large uncertainties due to the badly known decay constants, while the ratio $Delta Gamma_s / Delta M_s$ 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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