Seema Choudhury

12 November 2022

Abstract: We report the test of lepton flavor universality at Belle and Belle II experiments considering b -> c and b -> s transitions. We use 711/fb and 189/fb of data collected at Y(4S ) resonance from electron-positron collisions for Belle and Belle II, respectively. For the b -> c transition, we present the measurement of lepton-flavor-universality in B0 -> D*- l+nu decay, exclusive measurement of R(D) & R(D*) in Belle data, and inclusive R(Xe/mu) in Belle II. For the b -> s transitions, we provide measurements of R(K) and R(K*) using Belle data, measurement of the branching fraction for the decay B->K*ll, and test of lepton-flavor-universality in B->J/psiK using Belle II data. Additionally, we report the lepton-flavor-universality in Omega0_c -> omega-l+nu decay using 922/fb of data collected by the Belle detector.

Keyword(s): LFU, Belle, Belle II