O(N)-invariant S-matrix
= O(N)-invariant S-matrix
{c}
{title2=$S=S_2I+S_3P+S_1K$}
For particles in the <vector representation> of the <orthogonal group>, the two-body <S-matrix> is a linear combination of the identity $I$, permutation $P$ and trace contraction $K$: $S=S_2I+S_3P+S_1K$. Here $K(e_i\otimes e_j)=\delta_{ij}\sum_a e_a\otimes e_a$, $P^2=I$, $PK=KP=K$ and $K^2=NK$. The <orthogonal-invariant scattering channels> diagonalize these three operators simultaneously.