arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2006.01018hep-ph
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$X17$是由四个裸夸克组成的吗?

Is the $X17$ composed of four bare quarks?

Hua-Xing Chen

摘要:

在用QCD求和规则研究四夸克态时,我们发现了一些四夸克流,如$\bar u_L γ_μd_L~\bar d_L γ^μu_L$和$\bar u_L γ_μd_L~\bar d_R γ^μu_R$等,用算子乘积展开方法计算了它们的关联函数,发现非微扰QCD效应对它们的贡献不大.这表明可能存在由异常小质量的裸夸克组成的四夸克态。我们研究的可能分配的$X17$作为这样的状态。我们认为,原子实验可能会观察到一种新型的核衰变过程,其中海夸克带走了核的额外能量。这个四夸克分配的一个独特的特点是,我们预测两个几乎简并的状态具有显着不同的宽度。

英文摘要:

When studying tetraquark states using the method of QCD sum rules, we find some tetraquark currents, such as $\bar u_L γ_μd_L~\bar d_L γ^μu_L$ and $\bar u_L γ_μd_L~\bar d_R γ^μu_R$, etc. We calculate their correlation functions using the method of operator product expansion, and find that non-perturbative QCD effects do not contribute much to them. This indicates the possible existence of tetraquark states composed of bare quarks with abnormally small masses. We study the possible assignment of the $X17$ as such a state. We argue that the Atomki experiments might observe a new type of nuclear decay process, where sea quarks take away the extra energy of the nucleus. A unique feature of this tetraquark assignment is that we predict two almost degenerate states with significantly different widths.

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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