Ikeda Yoichi, Aoki Sinya, Doi Takumi, Gongyo Shinya, Hatsuda Tetsuo, Inoue Takashi, Iritani Takumi, Ishii Noriyoshi, Murano Keiko, Sasaki Kenji
Research Center for Nuclear Physics (RCNP), Osaka University, Osaka 567-0047, Japan.
Theoretical Research Division, Nishina Center, RIKEN, Saitama 351-0198, Japan.
Phys Rev Lett. 2016 Dec 9;117(24):242001. doi: 10.1103/PhysRevLett.117.242001.
The possible exotic meson Z_{c}(3900), found in e^{+}e^{-} reactions, is studied by the method of coupled-channel scattering in lattice QCD. The interactions among πJ/ψ, ρη_{c}, and D[over ¯]D^{} channels are derived from (2+1)-flavor QCD simulations at m_{π}=410-700 MeV. The interactions are dominated by the off-diagonal πJ/ψ-D[over ¯]D^{} and ρη_{c}-D[over ¯]D^{*} couplings, which indicates that the Z_{c}(3900) is not a usual resonance but a threshold cusp. Semiphenomenological analyses with the coupled-channel interaction are also presented to confirm this conclusion.
在 (e^{+}e^{-}) 反应中发现的可能的奇特介子 (Z_{c}(3900))，采用格点量子色动力学中的耦合通道散射方法进行研究。(\pi J/\psi)、(\rho\eta_{c}) 和 (D\overline{D}^{}) 通道之间的相互作用源自于在 (m_{\pi}=410 - 700,\text{MeV}) 下的 ((2 + 1)) 味量子色动力学模拟。这些相互作用主要由非对角的 (\pi J/\psi - D\overline{D}^{}) 和 (\rho\eta_{c} - D\overline{D}^{*}) 耦合主导，这表明 (Z_{c}(3900)) 不是一个常规共振态，而是一个阈值尖点。还给出了用耦合通道相互作用进行的半唯象分析以证实这一结论。
