1304.6433 (J. M. Dias et al.)

$Z_c^+(3900)$ decay width in QCD sum rules    [PDF]

J. M. Dias, F. S. Navarra, M. Nielsen, C. M. Zanetti

We identify the recently observed charmonium-like structure $Z_c^\pm(3900)$ as the charged partner of the X(3872) state. Using standard techniques of QCD sum rules, we evaluate the three-point function and extract the coupling constants of the $Z_c \, J/\psi \, \pi^+$ and $Z_c \, \eta_c \, \rho^+$ vertices and the corresponding decay widths in these channels. The good agreement with the experimental data gives support to the tetraquark picture of this state.

View original: http://arxiv.org/abs/1304.6433