XXVI. The mean life of charged V-particles

Abstract

Eight hundred tracks of slow particles have been photographed during a cloud chamber experiment on penetrating showers. Measurements of tracks produced by ten heavy, negative, non-decaying particles are presented. The total observed time of flight of these particles is l·6 × l0^-8 sec. After combining this time with the number of slow V-particles observed to decay in the cloud chamber, it is concluded that at least one type of heavy meson must have a mean life greater than 4 × 10^-9 sec.