TWO-DIMENSIONAL QCD WITH ADJOINT MATTER

Abstract

We review the recent work on the light-cone quantization of (1+1)-dimensional large N QCD coupled to adjoint matter. The spectrum of these models consists of glueball-like bound states which, in the large N limit, can be pictured as closed strings that cannot split or join. The pair creation (annihilation) inside the string is not suppressed even in the large N limit, giving rise to complex dynamics similar to that of genuine higher dimensional gauge theories. The mass spectra of such models exhibit an exponential growth of the density of states (Hagedorn behavior) and the absence of massless glueballs even in the case of massless constituents.