Orateur
Description
For over a decade, deviations (“B anomalies”) from the standard model have been observed in $b$-hadron decays, for example, the departure from the lepton flavor universality in $b \to s\ell\ell$ and $b \to c\tau\nu$ transitions. Many new physics models trying to explain these results have larger couplings with the $\tau$-lepton, being 3rd generation, which predict an enhanced branching fraction of $B \to K\tau\tau$ decay.
The talk describes how the Belle and Belle II experiments are searching for signatures of $B \to K\tau\tau$ decay using a hadronic B-tagging technique. The current B-tagging algorithm relies on machine learning and hence depends on the Monte Carlo modeling of hadronic B-decays. The improvement of the B-tagging performance through correcting the Monte Carlo description is also described.
