On the Meson Cloud around the Nucleons

Abstract

Hitherto, the research of the model of the elementary particles, that is, the study of the kinds of the elementary particles existing in the nature and their internal correlation, have been an important problem in the meson theory. Recently, various theories have been presented, which aim to investigate the structure of the elementary particles within the framework of the known models of the elementary particles or in connection with the divergence difficulties in the quantum field theory. I) Since the most problems in the present quantum field theory are related to the system of the field around its source, one of the most important researches of the elementary particles in the correspondence theoretical dew point is the investigation of the properties of the meson cloud of the nucleon system. In such problem we must be concerned with the field at a local spacetime which is not always on the surface at the time + 00 or 00 and so the Heisenberg representation is suitable for our purpose. In order to get the intuitive picture of the meson cloud we shall describe the meson cloud by uex, tI), which satisfies the homogeneous equation of the free meson field and coincides, on the world point xltl on the space-like surface d, with the field operator U(x) in the Heisenberg representation. Such operator U(x, d) was already introduced by Yang and Feldman.2) When we denote U(x, -(0) as U,nex), then there is an unitary transformation Sed) :2)