MEASUREMENTS OF CHARMED MESON LIFETIMES AND SEARCH FOR ${D^0} - {\overline D ^0}$ MIXING WITH THE BELLE EXPERIMENT

Abstract

The lifetimes of charmed mesons have been measured using 11.1fb$^{-1} of data collected with the Belle detector at KEKB. Each candidate is fully reconstructed to identify the flavor of the charmed meson. The lifetimes are measured to be $\tau(D^0)=(414.5\pm1.7)$ fs, $\tau(D^+)=(1029\pm12)$ fs and $\tau(D_s^+)=(488.4^{+7.8}_{-7.7})$ fs, where the error is statistical only. The mixing parameter $y_{CP}$ is also measured to be $y_{CP}=(1.16^{+1.67}_{-1.65}(stat.))%$ through the lifetime difference of $D^0$ mesons decaying into CP-mixed states and CP eigenstates.