LFU violations in leptonic τ decays and B-physics anomalies

We present a complete analysis of Lepton Flavor Universality (LFU) violations in leptonic τ decays in motivated models addressing the B-physics anomalies, based on the gauge group. We show that the inclusion of vector-like fermions, required by B-physics data, leads to sizable modifications of the leading-log results derived within an Effective Field Theory approach. In the motivated parameter-space region relevant to the B-physics anomalies, the models predict a few per-mil decrease of the effective W-boson coupling to τ, within the reach of future experiments