Precision measurement of the KS meson lifetime with the KLOE detector

Using a large sample of pure, slow, short lived K-0 mesons collected with KLOE detector at DA Phi NE, we have measured the K-S lifetime. From a fit to the proper time distribution we find tau(K-S) = (89.562 +/- 0.029(stat) +/- 0.043(syst)) ps. This is the most precise measurement to date of the short lived K-0 meson lifetime, in good agreement with the world average derived from previous measurements. We observe no dependence of the lifetime on the direction of the K-S in galactic coordinates.