Strong Z(c)(+)(3900) -> J/psi pi(+); eta c rho(+)decays in QCD

The widths of the strong decaysZ(c)(+)(3900) -> J/psi pi(+); and Z(c)(+) (3900) -> are calculated. To this end, the mass and decay constant of the exotic Z(c)(+) (3900) state are computed by means of a two -point sum rule. The obtained results are then used to calculate the strong couplings gz(c)J/psi pi and gz(c)eta(c)p employing QCD sum rules on the light cone supplied by a technique of the soft -meson approximation. We compare our predictions on the mass and decay widths \vith available experimental data and other theoretical results.