Measurements of semileptonic and leptonic B decays at Belle II

Introduction● New Belle II leptonic and semileptonic results using the full Run 1 dataset of365 fb -1 or 390M BB̅ pairs collected at an e+ e- centre-of-mass energy at theY(4S) resonance mass (10.58 GeV)● One new leptonic B decay result○ Measurement of the B + → τ ν branching fraction with a hadronic tagging method■ See Giovanni Gaudino’s YSF talk this evening for more details● Two new semileptonic B decay results○ Determination of |V cb| using B → D l ν decays with an inclusive tagging method○ Test of lepton flavour universality with measurements of R(D + ) and R(D∗+ ) usingsemileptonic B tagging■ First result using semileptonic B tagging !■ First combined R(D) and R(D*) Belle II measurement