Study of $N=2$ Superconformal Field Theories in $4$ Dimensions
  Making use of the exact solutions of the $N=2$ supersymmetric gauge theories we construct new classes of superconformal field theories (SCFTs) by fine-tuning the moduli parameters and bringing the theories to critical points. SCFTs we have constructed represent universality classes of the 4-dimensional $N=2$ SCFTs. 
Tohru Eguchi, Kentaro Hori, Katsushi Ito and Sung-Kil Yang