The energy spectrum of a self-coupled scalar field with two separate ground states is calculated using the variational method of RITZ. Two types of interacting particles are obtained. Their energies turn out to be finite after a suitable mass renormalization. Finally the possible physical consequences of the model are discussed.
w 1. IntroductionScience, since its birth, has been searehing for the ultimate unique ~'element" to which the whole variety of matter in .the universe may be reduced. After centuries spent in speculation, the theory of general relativity gave the first realistic promise to explain besides the gravitational field also the electromagnetic and other matter fields. Already one or two decades earlier, besides A. EINSTEIN, H. WEYL, E. SCHR()DINGER and other eminent scientists, also K. F. •OVOB 93 ~as engaged in the investigation of the mathematical possibilites of such a unified field theory. Nowadays many scientists try to realize this idea, which is thousands of years old, in the frame of the quantum field theory. Also the present paper was born under the influence of this tendency: a simple examp]e is investigated, which seemed to be apt to explain two different particles as two forros of one and the same field.Let us considera self-coupled scalar field [1] which is described by the field equation (1):1In the classical field theory this has several homogeneous --force-free --ground states, namely the solutions ~v ~ 0 and ~v --~ :~/x0/~ 0 V2. The lattcr are stable. The excitations of the field with small energy give rise to oscillations of small amplitude around the one of the other stable ground state. Ir may be expected that the quantum field theoretical treatment will lead to the conclusion that the scalar field described by (1) will account for two types of particles (quanta), which interact with each other. Investigating a model which in principle is similar D. J. BLOKHINTSEV was the first to propose the Acta Phys. Hung. Toro. XVII. Fa~r 1--2.