Mituo Taketani

Chapter 3. On the Structure of Lepton

The phenomenological and logical problems for the lepton structure are considered. The investigations are mainly concentrated on the difference between electron and muon, through the weak phenomena and also the electromagnetic phenomena. The remarkable mass difference between both particles is discussed from the standpoint of field theory. Finally a tentative scheme of the interrelation in the lepton family is proposed.

On the Origin of the Electron Mass

Some possibilities for understanding the dynamical origin of the electron mass are examined. As the present formulation of quantum electrodynamics does not give, within its region of validity, a satisfactory answer to this problem, two possibilities for obtaining the electron mass, starting from a zero bare mass, are presented. The first one is a nonlocal modification of quantum electrodynamics, which may be closely related to the electron structure. The other is to get the electron mass from the masses of other elemertary particles through weak interactions, because at the high energy region discussed, the weak interactions become more predominant compared to the electromagnetic interaction. These possibilities can be examined by improvements in experiments. The former depends on the experimental accuracies of the electron moment, and the latter is related to the degree of coexistence of S, P, and T couplings in coexistence with the main V and A couplings in beta decays and/or to the degree of the deviation from the V-A combination in the muon- electron interaction. (auth)

Theoretical Study of Cosmic Rays in Japan

No one would dispute the contributions of Japanese theoretical achievements to the development of cosmic ray research. However, the understanding of Japanese contributions is mostly limited to a general feeling, and many of the important details are overlooked and/or incorrectly advocated. This is due partly to the language barrier for foreigners, but also due greatly to talks and publications based on incorrect memory and unconscious distortions possibly affected by complex psychology. In order not to repeat such a mistake, I have written the present paper referring to my article “Formation of the Elementary Particle Theory Group” (Yukawa et al., 1951, 1965) written in 1950 when my memory was fresh and I was able to interview those who also had fresh memories.

On the Existence of a Boson µ0

It is shown that the existence of a mu 0 Bose meson is not inconsistent with experimental data. Possible decay modes of this meson are conjectured.

Meson Decays and Structure of Muon

Considering the peculiar position of the muon among the elementary particles, it seems reasonable to assume an inner structure for this particle. The analyses proposed are mainly connected to pion and muon decay problems. Assuming the so-called universal Fermi interaction with V and A couplings, by which the decay processes are realized, the considerations are restricted to the behaviors of the non-local form factor which arise from the muon structure. Also possibilities of the electron structure are discussed. The analysis depends on the deviation of the asymmetry parameter. Its deviations from the original local value must be within about 6%, and a value larger than this cannot be explained without consideration of the electron structure and some other sources. (auth)

RADIO EVOLUTION OF PULSARS.

Phenomenological analysis of radio evolution of pulsars is made. Under an assumption that the period of most of pulsars have a similar time dependence, the age t of pulsars is determined statistically from the observed spindown time t1 : t=0.30t1• Period P, radio luminosity during the pulse L, called simply the luminosity, and size of the radio-emitting region a, estimated as the pulse width times the light velocity, are shown to have time dependences of PoctO.SO±o.os, Loct0.70±0,t2 and aoct0.23±0.o& respectively. This radio evolution is compared with that of supernova remnants, quasi-stellar objects and radio galaxies directly or by means of the luminosity versus volume emissivity diagram. The evolutionary tracks are similar to each other in spite of different mechanisms involved. Finally the observed luminosity function N(L) ocL-t.50±0.os is compared with that calculated from the time dependence of the luminosity and it is shown that the slopes of the both functions are consistent with each other if the selection effect in the present sample of pulsars is taken into account. Similarly the birth rate of pulsars in the Galaxy is shown to be nearly equal to the explosion rate of type II supernovae after the selection effect is taken into account.

Neutrino Unified Model Based on Two Kinds of Neutrinos

Possible modifications of the neutrino unified model of elementary particles assuming the existence of two kinds of neutrinos are discussed. The hypotheses of the original neutrino unified model are replaced, and induced weak interactions and lepton and baryon currents in weak interactions are investigated. (C.E.S.)

Chapter 4. On the Neutrino Unified Model for Elementary Particles

The neutrino unified model for elementary particles is proposed and discussed with the connection of Sao Paulo and Nagoya Models. Since the model stands on the new interpretation of electric and baryonic charges, the consideration is concentrated to the roles of charges. Problems toward the unified theory along this model are also presented.

Chapter 2. A New Stage of Elementary Particle Theory

Elementary particle theory is reviewed and various outlooks of future developments are pointed out, Various models are discussed and the structure of elementary particles is treated.