论文标题
对充满迷人的Tetraquark State $ X（6900）$的内部结构的见解
Insights into the inner structures of the fully charmed tetraquark state $X(6900)$
论文作者
论文摘要
在有效范围扩展，综合关系和宽度饱和度以及耦合的多通道动力学研究的框架内分析了最近发现的充满迷人的Tetraquark候选$ X（6900）$。通过考虑到重夸克自旋对称性的约束，包括$ j/ψj/ψ，〜q0}χ_{c0} $和$χ_{C1}χ_{C1}χ_{C1} $的耦合通道振幅，包括$ 6. {C1} $ {C1}χ_{C1} $。还考虑了另一个动态的两耦合通道振幅，以及$ j/ψj/ψ$和$ψ（3770）J/ψ$的另一个动态耦合振幅也被认为描述了相同的数据集。三种不同的理论方法得出了类似的结论，即两烯膜组件在$ x（6900）$中没有扮演主导角色。我们发现，我们从精制耦合通道研究中对复杂能平面中的共振电线的测定与实验分析一致。耦合通道振幅也有另一根杆，对应于狭窄的共振$ x（6825）$，我们预测，$χ_{c0}χ_{C0} $阈值和分子起源。我们对$χ_{C0}χ_{C0} $和$χ_{C1}χ_{C1} $ Channels的线形形状进行预测，这可以为将来的实验测量提供有用的指南。
The recently discovered fully charmed tetraquark candidate $X(6900)$ is analyzed within the frameworks of effective-range expansion, compositeness relation and width saturation, and a coupled multichannel dynamical study. By taking into account constraints from heavy-quark spin symmetry, the coupled-channel amplitude including the $J/ψJ/ψ,~ χ_{c0}χ_{c0}$ and $χ_{c1}χ_{c1}$ is constructed to fit the experimental di-$J/ψ$ event distributions around the energy region near $6.9$ GeV. Another dynamical two-coupled-channel amplitude with the $J/ψJ/ψ$ and $ψ(3770) J/ψ$ is also considered to describe the same datasets. The three different theoretical approaches lead to similar conclusions that the two-meson components do not play dominant roles in the $X(6900)$. Our determinations of the resonance poles in the complex energy plane from the refined coupled-channel study are found to be consistent with the experimental analyses. The coupled-channel amplitudes also have another pole corresponding to a narrow resonance $X(6825)$ that we predict sitting below the $χ_{c0}χ_{c0}$ threshold and of molecular origin. We give predictions to the line shapes of the $χ_{c0}χ_{c0}$ and $χ_{c1}χ_{c1}$ channels, which could provide a useful guide for future experimental measurements.
