Manca Mrvar ; Christoph Schwanda

17 November 2021

Abstract: We report a measurement of the branching fraction of inclusive semileptonic B meson decays B -> Xc l nu in Υ(4S) -> BBbar data recorded by the Belle II experiment at the SuperKEKB asymmetric-energy e+e- collider and corresponding to 62.8/fb of integrated luminosity. Only a charged lepton (electon or muon) is reconstructed and the signal yield is determined from a fit to the lepton momentum distribution in the center-of-mass frame of the colliding beams. Averaging the result in the electron and muon channels, we find Br( B -> Xclnu ) = ( 9.75 +/- 0.03(stat) +/- 0.47(syst) )%.