The Possible $J^{PC}I^G=2^{++}2^+$ State X(1600)
  The interesting state X(1600) with $J^{PC}I^G=2^{++}2^+$ can't be a conventional $q \bar q$ meson in the quark model. Using a mixed interpolating current with different color configurations, we investigate the possible existence of X(1600) in the framework of QCD finite energy sum rules. Our results indicate that both the "hidden color" and coupled channel effects may be quite important in the multiquark system. We propose several reactions to look for this state. 
W. Wei, L. Zhang, Shi-Lin Zhu