Yulan Fan ; (on behalf of the Belle II collaboration)

13 October 2023

Abstract: Semileptonic 𝐵-meson decays involving the quark transition 𝑏 → 𝑐𝑙𝜈 provide excellent sensitivity to probe potential lepton-flavour universality violation. This work introduces two recent measurements related to tests of light-lepton flavour universality using a data sample collected at the Υ(4𝑆) resonance on the Belle II experiment corresponding to an integrated luminosity of 189/fb. Measurement of the ratio of the branching fractions of inclusive 𝐵 → 𝑋𝑒𝜈_𝑒 and 𝐵→ 𝑋 𝜇𝜈_𝜇 decays and measurement of angular asymmetries of 𝐵0 → 𝐷∗− 𝑙𝜈 decays agree well with standard model expectation.