The Vacuum Structure and Spectrum of N=2 Supersymmetric SU(N) Gauge   Theory
  We present an exact description of the metric on the moduli space of vacua and the spectrum of massive states for four dimensional N=2 supersymmetric SU(n) gauge theories. The moduli space of quantum vacua is identified with the moduli space of a special set of genus n-1 hyperelliptic Riemann surfaces. 
Philip C. Argyres and Alon E. Faraggi