arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2004.02106hep-ph
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手征组分夸克模型中的$QQ\bar{q}\bar{q}$

$QQ\bar{q}\bar{q}$ in a chiral constituent quark model

Yue Tan, Weichang Lu, Jialun Ping

摘要:

受LHCb和$X(5568)$的启发,我们研究了$QQ\bar{q}\bar{q}$($Q=c,b,s$,$q=u,d$)四夸克态.利用高斯展开方法,在手征夸克模型中系统地研究了双夸克-反夸克和介子-介子两种可能的色组态,寻找可能的稳定态。结果表明,等矢量$QQ\bar{q}\bar{q}$体系不存在束缚态,而等矢量$bb\bar{q}\bar{q}$、$cc\bar{q}\bar{q}$和$bc\bar{q}\bar{q}$体系存在较深的束缚态.在$QQ^{\prime}$体系中也存在几个浅束缚态。混合双夸克-反双夸克和介子-介子两种结构可以引入更多的吸引子,使一些非束缚的等熵态转变为浅束缚态。大质量的重夸克有利于束缚态的形成。通过计算夸克间的距离,揭示了系统的空间结构。

英文摘要:

Inspired by $Ξ_{cc}$ reported by LHCb Collaboration and $X(5568)$ reported by $D0$ Collaboration, the $QQ\bar{q}\bar{q}$ ($Q=c,b,s$, $q=u,d$) tetraquark states, are studied in the present work. With the help of gaussian expansion method, two structures, diquark-antiquark and meson-meson, with all possible color configurations are investigated systematically in a chiral quark model to search for the possible stable states. The results show that there is no bound state in the isovector $QQ\bar{q}\bar{q}$ system, while there are rather deep bound states in the isoscalar $bb\bar{q}\bar{q}$, $cc\bar{q}\bar{q}$ and $bc\bar{q}\bar{q}$ systems. There are also several shallow bound states in $QQ^{\prime}$ system. Mixing two structures of diquark-antidiquark and meson-meson can introduce more attractions and convert some unbound isoscalar states into shallow bound states. The large mass of the heavy quark is beneficial to the formation of the bound state. The separations between quarks are calculated to unravel the spacial structure of the system.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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