Consider three spin- nucleons (a simplified model of the triton
PHYSICS · Subjective · Fermi University Physics · Mathematical Methods for Physics · Quantum Mechanics · Symmetry, angular momentum and spin
Invariance, Ch Representations of Lie algebras: spin, products and SU(3)
Problem
Consider three spin-21 nucleons (a simplified model of the triton, ignoring isospin and orbital motion), each carrying the two-dimensional representation j=21 of su(2). Using the Clebsch-Gordan series χj1χj2=∑jχj applied twice, decompose the eight-dimensional product 21⊗21⊗21 into irreducible representations of total spin j, and check that the dimensions sum to 8.