New Nonlocal Charges in SUSY Integrable Models

In this letter, we study systematically the general properties of the $B$-extension of any integrable model. In addition to discussing the general properties of Hamiltonians, Hamiltonian structures etc, we also clarify the origin of "exotic" charges in such models. We show that, in such models, there exist at least two sets of non-local conserved charges (and more if $N>1$ supersymmetry is present) and that the "exotic" charges are part of this non-local charge hierarchy. The construction of these non-local charges from the Lax operator is explained.