Integrable double deformation of the principal chiral model
  We define a two-parameter family of integrable deformations of the principal chiral model on an arbitrary compact group. The Yang-Baxter sigma-model and the principal chiral model with a Wess-Zumino term both correspond to limits in which one of the two parameters vanishes. 
Francois Delduc, Marc Magro, Benoit Vicedo
hep-th