A Lesson from R τ τ K ( * ) $R_{\tau \tau }^{K^{(\ast )}}$ and R ν ν K ( * ) $R_{\nu \nu }^{K^{(\ast )}}$ at Belle II

Within the assumption of Left-Handed (LH) New Physics (NP), the relations between $B(B\to K^{(*)}{\tau }^{+}{\tau }^{-})$ and $B(B\to K^{(*)}\nu \overline{\nu })$ for several Beyond the Standard Model (BSM) scenarios are reviewed, commonly considered to explain the Lepton flavor Universality (LFU) violation observed in charged and neutral-current semileptonic B decays. The latest $R_{D^{(*)}}$ world averages that include the recent LHCb measurement and assess the possibility of simultaneously explaining B-anomalies without spoiling current bounds on di-neutrino and di-tau modes are employed. This is particularly relevant in light of the upcoming results by Belle II on neutrinos and the continuing improvement in accuracy and sensitivity achieved in tau modes.