Searches for New Physics in the Standard Model Processes

Measurement of the branching fraction R(D*); the ratio of the branching fraction of B0 to D*+ tau tau-neutrino over the branching fraction of B0 to D*+ lepton lepton-neutrino, where the lepton is either electron or muon. The tau lepton decays purely of leptonic: tau to electron electron-neutrino tau-neutrino and tau to muon muon-neutrino tau-neutrino. The B0 mesons are partially reconstructed where D*+ mesons are detected only through the soft pion daughters of the decay D*+ to D0 pi+. The data sample was collected at the Upsilon(4S) resonance with the Belle II detector at the SuperKEKB symmetric-energy e+e- collider.