Self-Organized Networks and Lattice Effects in High Temperature   Superconductors II: Fermi Arc Anomalies
  The self-organized dopant percolative filamentary model, entirely orbital in character (no fictive spins), explains the evolution with doping of Fermi arcs observed by ARPES, including the previously unexplained abrupt transitions in quasiparticle strength observed near optimal doping in cuprate high temperature superconductors. Similarly abrupt transitions are also observed in time-resolved picosecond relaxation spectroscopy at 1.5 eV, and these are explained as well, using no new assumptions and no adjustable parameters. 
J. C. Phillips