A Solution of the Generation Puzzle from Yang-Mills Duality
  A solution to the generation puzzle based on a nonabelian generalization of electric-magnetic duality is briefly reviewed. It predicts 3 and only 3 generations of fermions and explains the hierarchical mass spectrum as well as the main features in both the quark and lepton mixing matrices. A calculation to leading perturbative order already gives reasonable values to about half of the Standard Model parameters. 
H.M. Chan (Rutherford Appleton Lab) and S.T. Tsou (Oxford)