The splitting of a degenerate level under the action of a symmetry-breaking Hamiltonian

Abstract

Recently Biedenharn and Gamba (1972) described a simple group-theoretical method to calculate the quantitative splitting of a degenerate energy level under the action of a symmetry-breaking hamiltonian. The authors provide the general proofs for the rules of the method and clarify the group-theoretical background. Furthermore they discuss the various kinds of multiplicities which can arise and the difficulties which they entail.