Infrared behaviour of softly broken SQCD and its dual

Applying the recently obtained results on the renormalization of soft super symmetry-breaking parameters, we investigate the infrared behaviour of the softly broken supersymmetric QCD as well as its dual theory in the conforma l window. Under general assumptions on beta-functions, it is shown that the soft supersymmetry-breaking parameters asymptotically vanish in the infrar ed limit so that superconformal symmetry in softly broken supersymmetric QC D and in its dual theory revives at the infrared fixed point, provided the soft scalar masses satisfy certain renormalization group invariant relation s. If these relations are not satisfied, there exist marginal operators in both theories that lead to the breaking of supersymmetry and also colour sy mmetry. (C) 1998 Elsevier Science B.V. All rights reserved.