I was reading this paper and it'll form the basis of my undergrad thesis. The algebraic Bethe ansatz for scalar products in SU(3)-invariant integrable models I have a year to start and complete it. However my knowledge of Lie algebra is very lacking at this point. Could someone please explain to me what it means for an integrable model to be SU(3) invariant? I know that the elements of SU(3) are 3 x 3 unitary matricies with determinant equal to 1, so I'm assuming it means that something in the model is invariant under multiplication by these matricies?