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arXiv 2209.08802hep-ph
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$Z$衰变产生粲偶素的二阶前序QCD修正

Next-to-leading-order QCD correction to the exclusive double charmonium production via $Z$ decays

Xuan Luo, Hai-Bing Fu, Hai-Jiang Tian, Cong Li

摘要:

本文利用非相对论QCD因子化方法对双粲偶素通过$Z$ -玻色子衰变的唯一产生进行了进一步的研究,给出了QED图的单光子碎裂拓扑,QCD图与全QED图之间的干涉项,以及干涉项的次首阶计算。对于$Z$ -玻色子衰变中$J/ψ+J/ψ$的产生,由于加入了新计算的NLO QCD修正,干涉项显示出明显的唯象效应。在将所有贡献加在一起之后,分支分数$\mathcal{B}_{Z\to J/ψJ/ψ}$仍然明显低于CMS协作数据。此外,我们同时完成了$Z\to J/ψ+η_c (χ_{cJ})$和$J=(0,1,2)$的次首阶计算。计算结果表明,新计算的完全QED项和交叉项对总衰变宽度有明显的影响。

英文摘要:

In this paper, we preformed a further research on the exclusive productions of double charmonium via $Z$-boson decay by using nonrelativistic QCD factorizations approach, where the single-photon fragmentation topologies of the QED diagrams, the interference terms between the QCD and full QED diagrams, the next-to-leading-order calculations of the interference terms are preformed. For the production of $J/ψ+J/ψ$ in $Z$-boson decay, the interference terms show a significantly phenomenological effect due to the addition of the newly calculated NLO QCD corrections. After adding together all contributions, the branching fraction $\mathcal{B}_{Z\to J/ψJ/ψ}$ still undershoots the CMS collaboration data obviously. In addition, we simultaneously complete the next-to-leading-order calculations for $Z\to J/ψ+η_c (χ_{cJ})$ with $J=(0,1,2)$. The calculated results show that the newly-calculated complete QED and cross terms will have obvious effective on the total decay 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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