The L(sl_2) symmetry of the Bazhanov-Stroganov model associated with the   superintegrable chiral Potts model
  The loop algebra $L(\mathfrak{sl}_{2})$ symmetry is found in a sector of the nilpotent Bazhanov-Stroganov model. The Drinfeld polynomial of a $L(\mathfrak{sl}_{2})$-degenerate eigenspace of the model is equivalent to the polynomial which characterizes a subspace with the Ising-like spectrum of the superintegrable chiral Potts model. 
Akinori Nishino and Tetsuo Deguchi