GAUGE-THEORIES IN A BAG

We investigate multi-flavour gauge theories confined in (d = 2n)-dimen sional/euclidean bags. The boundary conditions for the 'quarks' break the axial-flavour symmetry and depend on a parameter theta. We determi ne the theta-dependence of the fermionic correlators and determinants and find that a CP-breaking theta-term is generated dynamically. As an application we calculate the chiral condensate in multi-flavour QED(2 ) and the abelian projection of QCD(2). In the second model a condensa te is generated in the limit where the number of colours, N-c, tends t o infinity. We prove that the condensate in QCD(2) decreases with incr easing bag radius R at least as similar to R(-1)/(NcNf). Finally we de termine the correlators of mesonic currents in QCD(2).