Deformation of conformal field theory as integrable models

Abstract

Preservation of Integrability when conformal field theory is deformed by perturbation along RG trajectory is discussed. The deformed theories are realized by massive theories and described by S-matrix under the appropriate bootstrap assumptions. Some deformations of minimal models are investigated and S-matrices are calculated only to yield all particles. Affine extensions of Toda field theory based on semi-simple Lie algebras are reviewed and we define the mass matrix and 3-point coupling.