Kinetic normal ordering and the induced non-abelian current in 1+1 dimensions

We show that the non-abelian current of massless fermions in 1+1 dimensions induced by an external gauge field can be unambiguously calculated. We use the hamiltonian formalism which is free of divergences and the normal ordering with respect to the vacuum in which all one-particle modes with negative kinetic energy are filled. The non-abelian current of Weyl fermions is gauge covariant and obeys the covariant anomaly equation. This current cannot be defined via functional derivatives. For Dirac fermions, kinetic normal ordering of the hamiltonian yields the correct vacuum functional. (orig.)