# Portorož 2017: New physics at the junction of flavor and collider phenomenology

Apr 18 – 21, 2017
Europe/Zurich timezone

## b -> s tau^+ tau^- polarization observables for FCC-ee

Apr 19, 2017, 3:16 PM
23m
Plenary talk

### Speaker

Luiz Vale Silva (JSI)

### Description

While one of the main motivations for the construction of the next collider facilities is the production of new particles, the debates around the relevant New Physics (NP) cases would be incomplete without low energy flavor studies. In this context, a rich pattern of deviations in B meson decays with respect to the Standard Model (SM) has brought much attention in recent years. Apart from the neutral current transition $b \rightarrow s \mu^+ \mu^-$, deviations have been seen in $\tau$ to light lepton ratios in charged current $b \rightarrow c$ decays, thus suggesting possible sources of lepton flavor universality violation beyond the SM, also hinted at by the ratio $R_K$. Here, I consider the measurement of the rare bottom decay $b \rightarrow s \tau^+ \tau^-$ by the electron-positron Future Circular Collider (FCC-ee), and discuss the short-distance physics information carried out by the $\tau^\pm$ polarizations.