ABSTRACT
This chapter discusses possible applications of gauge theories to the description of elementary-particle interactions. At present the theory of gauge fields has been universally adopted as the theoretical basis of elementary particle physics. Until the late sixties electrodynamics was the only example of successful applications in elementary-particle physics of quantum field theory in general and gaugeinvariant theories in particular. At the same time, it has been noticed for quite a while that weak and electromagnetic interactions have much in common. From experiments it is known that weak interactions involve vector currents. This leads to the idea that as in electrodynamics the interaction takes place through an exchange of vector particles, which have become known as intermediate bosons. Unlike the long-range electromagnetic interaction, the weak interaction has a finite interaction range, and consequently the corresponding vector fields must be massive.
