Tootfinder

$\mathcal{B}(B\rightarrow\tau\nu)$ measurement with the hadronic FEI at Belle~II
Giovanni Gaudino
https://arxiv.org/abs/2506.03000 https://

$\mathcal{B}(B\rightarrowτν)$ measurement with the hadronic FEI at Belle~II
We presented at Moriond EW 2025 a measurement of the branching fraction of $B\toτν$ decays using $(387\pm 6) \times 10^6$ $Υ(4S)$ collected between 2019 and 2022 with the Belle~II detector at the SuperKEKB $e^+e^-$ collider. We reconstruct the accompanying $B^-$ meson using the hadronic tagging method, while $B\toτν$ candidates are identified in the recoil. We find evidence for $B\toτν$ decays at 3.0 standard deviations, including systematic uncertainties. The measured branching fraction…