A coupled-channel lattice study of the resonance-like structure Zc (3900)
A coupled-channel lattice study of the resonance-like structure Zc (3900)
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类共振结构 Zc (3900) 的耦合通道晶格研究
DOI：
10.1088/1674-1137/43/10/103103
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Zhang Jianbo
中科院分区：
文献类型：
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作者：
Chen Ting;Chen Ying;Gong Ming;Liu Chuan;Liu Liuming;Liu Yubin;Liu Zhaofeng;Ma Jianping;Werner Markus;Zhang Jianbo
在这个探索性的研究中，我们用N_f=2+1+1扭转质量费米子组态的晶格QCD研究了D和D~*介子的近阈值散射。计算采用耦合通道Luscher有限尺寸形式。研究了具有I~G(J~(Pc))=1~+(1~(+-))的通道，发现了类共振结构Z_c(3900)。我们首先确定了两个最相关的通道，并在双通道散射模型中进行了晶格研究。结合双通道Ross-Shaw理论，通过求解广义本征值问题，从能级提取散射参数。我们对散射长度参数的结果表明，对于我们研究的特定晶格参数，最佳拟合参数并不对应于阈值附近的弹性散射截面中的峰值。此外，在零程Ross-Shaw理论中，在阈值附近出现窄共振的情况在3能级以上是不利的。
In this exploratory study, near-threshold scattering of D and D~* meson is investigated using lattice QCD with N_f=2+1+1 twisted mass fermion configurations. The calculation is performed in the coupled-channel Luscher finite-size formalism. The study focuses on the channel with I~G(J~(PC))=1~+(1~(+-)) where the resonance-like structure Z_c(3900) was discovered. We first identify the two most relevant channels and the lattice study is performed in the two-channel scattering model. Combined with the two-channel Ross-Shaw theory, scattering parameters are extracted from the energy levels by solving the generalized eigenvalue problem. Our results for the scattering length parameters suggest that for the particular lattice parameters that we studied, the best fit parameters do not correspond to the peak in the elastic scattering cross-section near the threshold. Furthermore, in the zero-range Ross-Shaw theory, the scenario of a narrow resonance close to the threshold is disfavored beyond the 3 level.