$\tau _{B_{s}}/\tau _{B_{d}}$ and $\Delta \Gamma _{s}$ confront new physics in $b\rightarrow s\tau \tau $

Several new physics scenarios that address anomalies in B-physics predict an enhancement of $$b \rightarrow s \tau \tau $$b → s τ τ with respect to its Standard Model prediction. Such scenarios necessarily imply modifications of the lifetime ratio $$\tau _{B_{s}}/\tau _{B_{d}}$$τ B s / τ B d and the lifetime difference $$\Delta \Gamma _{s}$$Δ Γ 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 $$\tau _{B_{s}}/\tau _{B_{d}}$$τ B s / τ B d and $$\Delta \Gamma _{s}$$Δ Γ s have the potential to provide bounds competitive with those directly extracted from $$b\rightarrow s \tau \tau $$b → s τ τ transitions. After performing a model-independent analysis, we apply our results to the particular case of leptoquark mediators proposed to address the $$R_{D^{(*)}}$$R D ( ∗ ) anomalies.