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We present some recent tests of lepton universality with semileptonic decays of B-mesons. The analyses are based on data collected at the (4S) resonance by the Belle II experiment, for an integrated luminosity of 189~fb^-1. \\ This report includes two key analyses focusing on over /e lepton universality. The first is the measurement of the branching-fraction ratio R (D^*/) =B (B D^* ^-ₑ) /B (B D^*^-_) using hadronic tagging. The second is the first measurement of the inclusive ratio R (X/) =B (B X ^-ₑ) /B (B X ^-_). \\ We also present the branching-fraction ratios R (X₄/) =B (B Xe^-ₑ) /B (B X^-_) and the first measurement of a comprehensive set of five angular asymmetries using B⁰ D^^+^- _ decays. \\ All results presented are consistent with their corresponding Standard Model predictions and, where applicable, with the experimental world averages.
G. Gaudino (Tue,) studied this question.