VACUUM-STRUCTURE OF 2-DIMENSIONAL GAUGE-THEORIES FOR ARBITRARY LIE-GROUPS

Using the well-established machinery of Wilson loop calculations we in vestigate the multiple vacua of two-dimensional Yang-Mills theories wi th infinitely massive adjoint matter. In particular, via group theoret ical techniques we calculate string tensions between charges and find the number of vacua for each compact Lie symmetry group. The counting of vacua is in agreement with the standard classification based on the topology of the effective gauge group pi(1)(G/Z) when one considers a rbitrary numbers of adjoint charges in the system. For systems with li mited numbers of charges we find additional ''meta-stable'' vacuum sta tes. Finally we discuss 't Hooft's disorder operators in this setting as number operators for the multiple vacua. (C) 1997 Elsevier Science B.V.