BRANES, SUPERPOTENTIALS AND SUPERCONFORMAL FIXED-POINTS

We analyze various brane configurations corresponding to field theorie s in three, four and five dimensions, We find brane configurations whi ch correspond to three-dimensional N = 2 and four-dimensional N = 1 su persymmetric QCD theories with quartic superpotentials, in which what appear to be ''hidden parameters'' play an important role. We discuss the construction of five-dimensional N = 1 supersymmetric gauge theori es and superconformal fixed points using branes, which leads to new fi ve-dimensional N = 1 superconformal field theories. The same five-dime nsional theories are also used, in a surprising way, to describe new s uperconformal fixed points of three-dimensional N = 2 supersymmetric t heories, which have both ''electric'' and ''magnetic'' Coulomb branche s. (C) 1997 Elsevier Science B.V. PACS: 11.10.Kk; 11.30.Pb.