Measurement of Charmed Meson Lifetimes with Belle

Abstract

The lifetimes of charmed mesons have been measured using 2.75fb$^{-1}$ 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 $τ(D^0)=(414.8\pm3.8\pm3.4)$ fs, $τ(D^+)=(1040^{+23}_{-22}\pm18)$ fs and $τ(D_s^+)=(479^{+17}_{-16}{}^{+6}_{-8})$ fs, where the first error is statistical and the second error is systematic. The mixing parameter $y_{CP}$ is also measured through the lifetime difference of $D^0$ mesons decaying into CP-mixed states and CP eigenstates. We find $y_{CP}=(1.0^{+3.8}_{-3.5}{}^{+1.1}_{-2.1})%$, corresponding to a 95% confidence interval $-7.0%<\ycp<8.7%$.