X, Y and Z States
  Many new states in the charmonium mass region were recently discovered by BaBar, Belle, CLEO-c, CDF, D0, BESIII, LHCb and CMS Collaborations. We use the QCD Sum Rule approach to study the possible structure of some of these states. 
M. Nielsen, R.M. Albuquerque, J.M. Dias, K.P. Khemchandani, A.   Martinez Torres, F.S. Navarra and C.M. Zanetti
hep-ph nucl-th