Precision Measurement of KS Meson Lifetime with the KLOE detector

Using a large sample of pure, slow, short lived \ko\ mesons collected with KLOE detector at \DAF, we have measured the \ks\ lifetime. From a fit to the proper time distribution we find $\ts = (89.562 \pm 0.029_{\rm{stat}}\pm 0.043_{\rm{syst}})$ ps. This is the most precise measurement today in good agreement with the world average derived from previous measurements. We observe no dependence of the lifetime on the direction of the \ks.