Possible Phases in Strong Interaction Vacuum
  A study of the possible vacuum phases in a strongly interacting two flavor light quark system is presented. Four possible phases are found with some of their properties presented. The possible existence of localized U(1) EM symmetry breaking phases inside a nucleon and excited hadrons is investigated by showing the potential of solving three selected current ``puzzles'' in experimental obervations if such a possibility is taken into account. Base on these results, the potential of producing these phases in heavy ion collisions is speculated. 
S. Ying (Phys. Dept., Fudan Univ., Shanghai, China)