A New Perspective towards the Theory of Elementary Particles

Abstract

With the remarkable progress made in the theory of elementary particles, the issue concerning the results achieved so far, has been made much clearer. We are now in a situation to be obliged to have a new perspective and a new strategy including the possibility of taking a slightly different approach in the investigation of the theory of elementary particles. Of the great results accomplished during a few years after the Second World War, we should, first of all, note the brilliant results of the renormali­ zation method in the quantum field theory presented by Tomonaga and others, (i.e., the Tomonaga-Schwinger method), which made the quantum electro­ dynamics extremely precise. Secondly the progress made in the meson theory must be noted, this review has been reported through a meeting held at Research Institute for Fundamental Physics in Kyoto last autumn. It clearly shows that the research program of Taketani in the study of nuclear force was correct. We found that the cut-off hypothesis is valid not only in the problem of the nuclear force, but also in the meson theory, especially in the phenomena related to the P-wave part of the meson field with a good agreement with experiments. However, the problem concerning the S­ wave part appears not so successful as that concerning the P-wave part. The problem of the S-wave part has to be left to the future, along with the problem of the nature of the core in the nuclear force. On the other hand, a recent study of the quantum electrodynamics (Q.E.D.) through the renormalization method seems to show that the internal contradiction inherent in Q.E.D. can no longer be disregarded. Especially the recent works performed by Kallen-Pauli, Landau and Pomeranchuk, after the proposal of the so-called ghost problem, suggest that the present field theory is never entirely correct even, in Q.E.D. The quantum meso-dyna­ mics has so far been considered to be less reliable than Q.E.D., but the problem, which was hitherto hidden behind the cut-off procedure, became more serious. These facts imply the necessity of a drastic change in the field theory, though one can, of course, never exclude a possibility of making the situation better by the improvement of approximation method in a *' Editors' note: Translated from the lecture (without title) at the Symposium on Field Theory held at Research Institute for Fundamental Physics in spring 1956. The lecture was arranged in this form by H. Kita and published in Soryushiron Kenkyu (Mimeographed Circular in Japanese) 12 (1956), pp. 296~303. The above title is given by the Editor.