Super- and CP-symmetric QCD in Higher Dimensions
  An extremely precise global symmetry is necessary in the Peccei--Quinn solution to the strong CP problem. Such symmetry arises when colored chiral fermions are localized in an internal space. We present a supersymmetric model that incorporates the above mechanism. Extra colored chiral multiplets around the supersymmetry-breaking scale are a generic prediction of the supersymetric model. 
K.-I. Izawa, Taizan Watari, and T. Yanagida