Wigner and the groups in classifying elementary particles and nuclear states

Abstract

Abstract. The application of group-representations in nuclear and particle physics, as initiated by Wigner [1], is considered. The general classification of the elementary particles according to the representations of the inhomogenous Lorentz-group [2] is recalled. The role of the U(4) group is discussed, first in relation with the spin-isospin supermultiplets [3] both in nuclear and in particle physics, then as a dynamical group of the two-body systems in both disciplines. Finally the classification of the nuclear states is mentioned both for the single shell, and for the multi-shell problems.