The SU(2) Hidden Substructure of Quarks and the Kobaiashi-Maskawa Matrix
  It is proposed that each quark is composed of two prequarks, called primons. This composition generates a new hypercharge and a new kind of color called supercolor. Such quark composition explains the Kobaiashi-Maskawa matrix elements in terms of selection rules based on the new hypercharge. Also it is shown that the doublet of quarks top/bottom is quite similar to the doublet charm/strange. Besides, it is also shown that there should exist three Higgs bosons involved in the generation of quark masses. 
Mario Everaldo de Souza