Measurement of the B0 lifetime and flavor-oscillation frequency using hadronic decays reconstructed in 2019-2021 Belle II data

作者：Ablikim, M.; Achasov, M. N.; Adlarson, P.; Ahmed, S.; Albrecht, M.; Amoroso, A.; An, Q.; Bai, X. H.; Bai, Y.; Bakina, O.; Ferroli, R. Baldini; Balossino, I; Ban, Y.; Begzsuren, K.; Bennett, J., V; Berger, N.; Bertani, M.; Bettoni, D.; Bianchi, F.; Biernat, J.; Bloms, J.; Bortone, A.; Boyko, I; Briere, R. A.; Cai, H.; Cai, X.; Calcaterra, A.; Cao, G. F.; Cao, N.; Cetin, S. A.; Chang, J. F.; Chang, W. L.; Chelkov, G.; Chen, D. Y.; Chen, G.; Chen, H. S.; Chen, M. L.; Chen, S. J.; Chen, X. R.

来源：Physical Review D, 2023, 107(9): L091102.

DOI：10.1103/PhysRevD.107.L091102

We measure the B-0 lifetime and flavor-oscillation frequency using B-0 -> D(*)-x+ decays collected by the Belle II experiment in asymmetric-energy e+e- collisions produced by the SuperKEKB collider operating at the T(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 zB(0) = (1.499 +/- 0.013 +/- 0.008) ps, Amd = (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.