CANONICAL-TRANSFORMATIONS IN A HIGHER-DERIVATIVE FIELD-THEORY

It has been suggested that the chiral symmetry can be implemented only in classical Lagrangians containing higher covariant derivatives of o dd order. Contrary to this belief, it is shown that one can construct an exactly soluble two-dimensional higher-derivative fermionic quantum field theory containing only derivatives of even order whose classica l Lagrangian exhibits chiral-gauge invariance. The original field solu tion is expressed in terms of usual Dirac spinors through a canonical transformation, whose generating function allows the determination of the new Hamiltonian. It is emphasized that the original and transforme d Hamiltonians are different because the mapping from the old to the n ew canonical variables depends explicitly on time. The violation of cl uster decomposition is discussed and the general Wightman functions sa tisfying the positive-definiteness condition are obtained.