Abstract:
These lectures given by Professor B. Zumino, Chairman, Department of Physics, New York University, while visited The Institute as Visiting Professor, for which the notes were prepared by N.R. Ranganathan, K. Venkatesan and G. Jagannathan. These lectures deals with Gauge groups of a special kind, the familiar gauge transformation of the first kind - in Quantum Mechanics. In SU3 symmetry scheme for elementary particles Gell-Mann and Glashow break Gauge invariance by giving a kinematical mass to the vector meson. The other possibility is that though gauge invariance implies that the bare mass of the particle vanishes, the physical mass need not(Sakurai & Schwinger). This report critically reviews the various arguments, to prove that either the physical or the bare mass vanishes when there is invariance under gauge groups.