SU(3) Clebsch-Gordan coefficients and some of their symmetries

Abstract

We discuss the construction and symmetries of su(3) Clebsch-Gordan coefficients arising from the su(3) basis states constructed as triple tensor products of two-dimensional harmonic oscillator states. Because of the su(2) symmetry of the basis states, matrix elements and recursion relations are easily expressed in terms of su(2) technology. As the Weyl group has a particularly simple action on these states, Weyl symmetries of the su(3) coupling coefficients generalizing the well known m-> -m symmetry of su(2) coupling can be obtained, so that any coefficient can be obtained as a sum of Weyl-reflected coefficients lying in the dominant Weyl sector. Some important cases of multiplicity-free decomposition are discussed as examples of applications.