Several new physics scenarios that address anomalies in $B$-physics predict an enhancement of $b \rightarrow s \tau \tau$ with respect to its Standard Model prediction. Such scenarios necessarily imply modifications of the lifetime ratio $\tau_{ B_{ s}}/\tau_{ B_{ d}}$ and the lifetime difference $\Delta\Gamma_{ s}$. In this work, we explore indirect bounds provided by these observables over new physics scenarios. We also estimate future projections, showing that future experimental and theoretical improvements on both $\tau_{ B_{ s}}/\tau_{ B_{ d}}$ and $\Delta\Gamma_{ s}$ have the potential to provide bounds competitive with those directly extracted from $b\rightarrow s \tau \tau$ transitions. After performing a model-independent analysis, we apply our results to the particular case of leptoquark mediators proposed to address the $R_{ D^{ (*)}}$ anomalies.
Categories: hep-ph hep-ex