The meson $Z^+(4430)$ as a tetraquark state

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We test the validity of the QCD sum rules applied to the meson $Z^+(4430)$, by considering a diquark-antidiquark type of current with $J^{P}=0^{-}$ and with $J^{P}=1^{-}$.

• We find that, with the studied currents, it is possible to find an acceptable Borel window.
• In such a Borel window we have simultaneously a good OPE convergence and a pole contribution which is bigger than the continuum contribution.
• We get $m_Z=(4.52\pm0.09)\GeV$ and $m_Z=(4.84\pm0.14)\GeV$ for the currents with $J^{P}=0^{-}$ and $J^{P}=1^{-}$ respectively.