Yukio Taguchi

A finite formulation of renormalizable field theory based on improved operator products

Abstract A finite local theory is formulated by improving the notion of operator products. The improvement is performed with the aid of field theory inn dimensions. Our theory is closely connected with renormalization theory. For example, both theories give the same results for the observables. However, in our theory, any physical object except the Lagrangian is finite as a density and calculations at the operator level, including the equal- time commutators, are reliable. Then the discussion on anomalies can be done at that level. The renormalization group equation is derived within the framework of our theory. The formulation is illustrated with the ϕ4 theory in four dimensions.

Hyperon Decays and Characteristics of Interactions between Elementary Particles

The weak interactions describing decays of elementary particles have some regularity and universality. The Fermi-type weak fermion interaction with the same universal coupling constants for parity conserving and nonconserving terms has explained successfully the nuclear beta decay and μ-e decay. As for the pion and K-meson decays, it also seems that the universal weak boson fermion interaction of gradient type with the same amount of even and odd parts is more desirable than the direct type coupling. As for the hyperon decays, recent observations on the angular assymmetries have appeared to emphasize a similar tendency. Calculated results are presented in tables and figures.

Haag's theorem and dimensional regularization

Abstract It is shown that dimensionally regularized field theories are free from the difficulty in Haags theorem, which states that there exists no relativistic theory with interaction in which the Fock representation is used.

A finite formulation of quantum electrodynamics based on improved operator products

Abstract The improved product formulation of local field theory, proposed in an earlier paper, is applied to quantum electrodynamics. By virtue of the improvement of operator products, calculations at the operator level become reliable and the Lorentz and gauge invariances of the theory become transparent. The improvement is performed with the aid of field theory in n dimensions. The main purpose of this paper is to discuss how to treat the gauge invariance and its related problems within the framework of our finite theory.