The mass, coupling and width of the newly observed charged resonance $ Z_{ c}^{ -}(4100)$ are calculated by treating it as a scalar four-quark system with a diquark-antidiquark structure. The mass and coupling of the state $ Z_{ c}^{ -}(4100)$ are calculated using the QCD two-point sum rules. In these calculations we take into account contributions of the quark, gluon and mixed condensates up to dimension ten. The spectroscopic parameters of $ Z_{ c}^{ -}(4100)$ obtained by this way are employed to study its $S$-wave decays to $\eta_c(1S)\pi^{ -}$, $\eta_c(2S)\pi^{ -}$, $D^{ 0}D^{ -}$, and $ J/\psi \rho ^{ -}$ final states. To this end, we evaluate the strong coupling constants corresponding to the vertices $Z_{ c}\eta_c(1S)\pi^{ -}$, $ Z_{ c}\eta_c(2S)\pi^{ -}$, $Z_{ c}D^{ 0}D^{ -}$, and $Z_{ c}J/\psi \rho^{ -}$ respectively. The couplings $g_{ Z_c\eta_{ c1} \pi}$, $g_{ Z_{ c}\eta_{ c2} \pi}$ , and $g_{ Z_{ c}DD}$ are computed by means of the QCD three-point sum rule method, whereas $g_{ Z_{ c}J/\psi \rho }$ is obtained from the QCD light-cone sum rule approach and soft-meson approximation. Our results for the mass $ m=(4080 \pm 150)~\mathrm{ MeV}$ and total width $\Gamma =(147 \pm 19)~\mathrm{ MeV}$ of the resonance $Z_{ c}^{ -}(4100)$ are in excellent agreement with the existing LHCb data.
Categories: hep-ph hep-ex hep-lat