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arXiv · 1706.07300

The Tetraquark Candidate Zc(3900) from Dynamical Lattice QCD Simulations

Yoichi Ikeda
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Abstract

The structure of the tetraquark candidate $Z_{c}(3900)$, which was experimentally reported in $e^+ e^-$ collisions, is studied by the s-wave meson-meson coupled-channel scattering on the lattice. The s-wave interactions among the $πJ/ψ$, $ρη_{c}$ and $D \bar{D}^{*}$ channels are derived from (2+1)-flavor dynamical QCD simulations at $m_π=410$--$700$ MeV. It is found that the interactions are dominated by the off-diagonal $πJ/ψ$-$D \bar{D}^{*}$ and $ρη_{c}$-$D \bar{D}^{*}$ couplings. With the interactions obtained, the s-wave two-body amplitudes and the pole position in the $πJ/ψ$-$ρη_{c}$-$D \bar{D}^{*}$ coupled-channel scattering are calculated. The results show that the $Z_{c}(3900)$ is not a conventional resonance but a threshold cusp. A semiphenomenological analysis with the coupled-channel interaction to the experimentally observed decay mode is also presented to confirm the conclusion.

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Yoichi Ikeda. 2017-06-21. The Tetraquark Candidate Zc(3900) from Dynamical Lattice QCD Simulations. https://doi.org/10.1088/1361-6471%2Faa9afd

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