Understanding close-lying exotic charmonia states within QCD sum rules
  Motivated by the experimental findings of some new exotic states decaying into channels like $J/\psi \phi$, we investigate the formation of resonances/bound states in the $D^*_s\bar D^*_s$ system using QCD sum rules. To do this we start with a current of the type vector times vector and use spin projectors to separate the spin 0, 1 and 2 contributions to the correlation function. We find three states with isospin 0, nearly spin degenerate, with a mass around 4.1 GeV. We have also investigated the decay of these states to $J/\psi \phi$ and provide the corresponding partial widths. Such information should be useful for experimental studies in future. 
A. Mart\'inez Torres, K. P. Khemchandani, J. M. Dias, F. S. Navarra,   M. Nielsen
hep-ph nucl-th