$Z_c^{+}(3900)$ decay width in QCD sum rules

Abstract

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.

Comments: new section and two more figures added