CV. Masses and modes of decay of heavy mesons.—<i>Part II</i>. τ-particles

Abstract

Summary 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±8me . 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.