Charmonium meson and hybrid radiative transitions
  We consider the non-relativistic limit of the QCD Hamiltonian in the Coulomb gauge, to describe radiative transitions between conventional charmonium states and from the lowest multiplet of $c\bar{c}$ hybrids to charmonium mesons. The results are compared to potential quark models and lattices calculations. 
Peng Guo, Tochtli Y\'epez-Mart\'inez, Adam P. Szczepaniak
hep-ph hep-lat