We measure the B0 lifetime and flavor-oscillation frequency using B0→D(*)−π+ decays collected by the Belle II experiment in asymmetric-energy e+e− collisions produced by the SuperKEKB collider operating at the Υ(4S) resonance. We fit the decay-time distribution of signal decays, where the initial flavor is determined by identifying the flavor of the other B meson in the event. The results, based on 33000 signal decays reconstructed in a data sample corresponding to 190 fb−1, are τB0=(1.499±0.013±0.008) ps, Δmd=(0.516±0.008±0.005) ps−1, where the first uncertainties are statistical and the second are systematic. These results are consistent with the world-average values.
