Extended Color Models with a Heavy Top Quark
  We present a class of models in which the top quark, by mixing with new physics at a higher energy scale, is naturally heavier than the other standard model particles. We take this new physics to be extended color. Our models contain new particles with masses between 100 GeV and 1 TeV, some of which may be just within the reach of the next generation of experiments. In particular one of our models implies the existence of two right handed top quarks. These models demonstrate the existence of a standard model-like theory consistent with experiment, and leading to new physics below the TeV scale, in which the third generation is treated differently than the first two. 
Oscar F. Hernandez