CIV. Masses and modes of decay of heavy mesons.— Part I . κ-particles

Summary Observations by the photographic method are described which establish the existence of heavy charged mesons, of mass about 1200me , which decay with the emission of a single charged particle. In one case, it is shown that the secondary charged particle is a μ-meson of energy 5·9 MeV. In another, it is a particle of charge |e| and of energy about 200 MeV. If the two particles are of the same type with similar modes of decay, then the charged secondary particle must be accompanied by at least two neutral particles. The question whether the κ-particles are identical with the τ-mesons which decay into three charged particles, is discussed.