We report a measurement of the $D^0$ and $D^+$ lifetimes using $D^0\to K^-\pi^+$ and $D^+\to K^-\pi^+\pi^+$ decays reconstructed in $e^+e^-\to c\bar{ c}$ data recorded by the Belle II experiment at the SuperKEKB asymmetric-energy $e^+e^-$ collider. The data, collected at center-of-mass energies at or near the $\Upsilon(4S)$ resonance, correspond to an integrated luminosity of $72\,{ \rm fb}^{ -1}$. The results, $\tau(D^0) = 410.5\pm1.1\,{ \rm(stat)}\pm0.8\,{ \rm(syst.)}\,{ \rm fs}$ and $\tau(D^+) = 1030.4\pm4.7\,{ \rm(stat)}\pm3.1\,{ \rm(syst.)}\,{ \rm fs}$, are the most precise to date and are consistent with previous determinations.
Categories: hep-ex