THE CONDENSATE FOR QCD(1+1) COUPLED TO ADJOINT FERMIONS

We consider SU(2) Yang-Mills theory in 1 + 1 dimensions coupled to mas sless adjoint fermions. With all fields in the adjoint representation, the gauge group is actually SU(2)/Z(2) which possesses nontrivial top ology. In particular, there are two distinct topological sectors and t he physical vacuum state has a structure analogous to a theta vacuum b ut the theta angle is determined to +/-pi/2 by the symmetries of the t heory. We show how this feature is realized in light-front quantizatio n, using discretization of x(-) as an infrared regulator. We find exac t expressions for the vacuum states and we calculate the bilinear cond ensate of the model. We argue that this condensate does not effect the spectrum of the massless theory but gives the string tenson of the ma ssive theory. (C) 1997 Published by Elsevier Science B.V.