CV. Masses and modes of decay of heavy mesons.-Part II. τ-particles

Abstract

Further evidence which establishes the existence of heavy charged mesons which decay into three charged particles is presented. It is shown that the three secondary particles are probably π-particles, and that the mass of the parent mesons, called τ-particles, is 966±8m_e. The frequency of occurrence of κ- and τ-particles at the Jungfraujoch, in comparison with the number of π-particles, is discussed, and it is shown that in the nuclear collisions involving protons of energy greater than 10 BeV., a large fraction of the energy lost in the creation of mesons, must appear as κ- and τ-particles. The evidence suggests that the life-time of the heavy mesons is about 10^-9 sec. The most favourable conditions for the detection of the particles by the photographic method are discussed.