Mixing and lifetimes of $b$-hadrons

TL;DR

This paper reviews the current understanding of $b$-hadron mixing and lifetimes, emphasizing the potential of certain observables to detect new physics and connecting lifetime measurements to theoretical precision in mixing parameters.

Contribution

It highlights the importance of $ au_{b}$-hadron lifetime measurements in testing theoretical predictions of mixing parameters and provides a numerical estimate for the $ au_{ ext{Xi}_b}$ baryon lifetime.

Findings

$ au_{b}$-hadron lifetime measurements can test theoretical predictions.

$rac{ ext{GAMMA}_{12}}{ ext{M}_{12}}$ precision can be validated through lifetime analysis.

Numerical estimate for $ au_{ ext{Xi}_b}$ baryon lifetime provided.

Abstract

We review the status of mixing and lifetimes of $b$-hadrons. We will show that $\Delta \Gamma / \Delta M$, $a_{sl}$ and $\phi$ are better suited to search for new physics effects than $\Delta M$ alone, because of our poor knowledge of the decay constants. The theoretical precision in the determination of $\Gamma_{12} / M_{12}$ - which contains all information on $\Delta \Gamma / \Delta M$, $a_{sl}$ and $\phi$ - 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 $\Xi_b$-baryon.