  Exploration of the resonances $Z_c(3900)$ and $Z(4430)$ are performed by
assuming that they are ground-state and first radial excitation of the same
tetraquark with $J^{P}=1^{+}$. The mass and current coupling of the $
Z_c(3900)$ and $Z(4430)$ states are calculated using QCD two-point sum rule
method by taking into account vacuum condensates up to eight dimensions. We
investigate the vertices $Z_cM_hM_l$ and $ZM_hM_l$, with $M_h$ and $M_l $ being
the heavy and light mesons, and evaluate the strong couplings $ g_{Z_cM_hM_l}$
and $g_{ZM_hM_l}$ using QCD sum rule on the light cone. The extracted couplings
allow us to find the partial width of the decays $ Z_c(3900) \to J/\psi \pi;
\,\psi^{\prime} \pi;\, \eta_c \rho$ and $Z(4430) \to \psi^{\prime} \pi;\,
J/\psi \pi;\, \eta_c^{\prime}\rho;\, \eta_c\rho$, which may help in
comprehensive investigation of these resonances. We compare width of the decays
of $Z_c(3900)$ and $Z(4430)$ resonances with available experimental data as
well as existing theoretical predictions.
