Precise measurements of $D$ meson lifetimes

Abstract

We report the result of $D^0$ and $D^{+}$ lifetime measurement using $D^0\to K^{-}{\pi }^{+}$ and $D^{+}\to K^{-}{\pi }^{+}{\pi }^{+}$ decays reconstructed using $72\mathrm{f}{\mathrm{b}}^{-1}$ of data collected by the Belle II experiment at SuperKEKB asymmetric-energy $e^{+}{e}^{-}$ collider. The results, $\tau (D^0)=410.5\pm 1.1(\mathrm{stat})\pm 0.8(\mathrm{syst})\mathrm{fs}$ and $\tau (D^{+})=1030.4\pm 4.7(\mathrm{stat})\pm 3.1(\mathrm{syst})\mathrm{fs}$, are the most precise to date and are consistent with previous measurements.