$τ_{B_{s}}/τ_{B_{d}}$ and $ΔΓ_{s}$ confront new physics in $b\to sττ$

Abstract

Several new physics scenarios that address anomalies in $B$-physics predict an enhancement of $b \rightarrow s ττ$ with respect to its Standard Model prediction. Such scenarios necessarily imply modifications of the lifetime ratio $τ_{B_{s}}/τ_{B_{d}}$ and the lifetime difference $ΔΓ_{s}$. 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 $τ_{B_{s}}/τ_{B_{d}}$ and $ΔΓ_{s}$ have the potential to provide bounds competitive with those directly extracted from $b\rightarrow s ττ$ 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.