EFFECTIVE-HAMILTONIANS FOR 1 N EXPANSION IN 2-DIMENSIONAL QCD/

We discuss the general structure of effective hamiltonians for systema tic 1/N expansion in QCD using the light-cone quantization. These are second-quantized hamiltonians acting on the Fock space of mesons and g lueballs defined by the solution of the N = infinity problem. In the t wo-dimensional case we find only cubic and quartic interaction terms, and give explicit expressions for the vertex functions as integrals of solutions of 't Hooft equation. As examples of possible applications of our formalism, we study 1/N corrections to meson mass and form fact ors for decays of Q $$($) over bar q states, recently discussed by Gri nstein and Mende in the large-N limit. We find that 1/N is a good smal l expansion parameter.