Towards Partial Compositeness on the Lattice: Baryons with Fermions in   Multiple Representations
  We describe our recent lattice study of SU(4) gauge theory with fermions in the fundamental and sextet representations. In this theory, a new type of baryon consists of quarks in both representations. The spectrum of these "chimera baryons" has a straightforward interpretation in terms of a non-relativistic quark model based on SU(4). Our results are particularly relevant to composite Higgs models in which the top quark is partially composite. 
Thomas A. DeGrand, Daniel Hackett, William I. Jay, Ethan T. Neil,   Yigal Shamir, Benjamin Svetitsky
hep-lat hep-ph