Precise measurement of the $D^0$ and $D^{+}$ lifetimes at Belle II

Abstract

We report a measurement of the $D^0$ and $D^{+}$ lifetimes using $D^0\to K^{-}\ddot{I}{€}^{+}$ and $D^{+}\to K^{-}\ddot{I}{€}^{+}\ddot{I}{€}^{+}$ 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 $\hat{I}\yen (4S)$ resonance, correspond to an integrated luminosity of $72{\mathrm{fb}}^{-1}$. The results, $\ddot{I}„(D^0)=410.5\pm 1.1(\mathrm{stat})\pm 0.8(syst.)\mathrm{fs}$ and $\ddot{I}„(D^{+})=1030.4\pm 4.7(\mathrm{stat})\pm 3.1(syst.)\mathrm{fs}$, are the most precise to date and are consistent with previous determinations.

9 pages, 2 figures