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arXiv 2205.06124hep-phhep-ex
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$Υ$衰变为双charmonia的高阶QCD修正

Higher-order QCD corrections to $Υ$ decay into double charmonia

Yu-Dong Zhang, Wen-Long Sang, Hong-Fei Zhang

备注：
13 pages, 2 figures, 3 tables, to match the version accepted for publication in PRL
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摘要：

在这项工作中，我们研究了$Υ$到$J/ψ$与$η_c$（$χ_{c0,1,2}$）的排他性衰变。在非相对论QCD框架下，计算了不同螺旋度位形的衰变宽度。我们发现，QCD修正显着减轻了所有过程的衰变宽度的重整化标度依赖。$Υ\rightarrow J/ψ+χ_{c1}$的支化分数以$3.73^{+5.10+0.10}_{-2.06-1.19}\times 10^{-6}$获得，其与Belle测量结果一致，即，${\rm Br}(Υ\rightarrow J/ψ+χ_{c1})=(3.90\pm1.21\pm0.23)\times10^{-6}$。对于其他过程，我们的分支分数的结果是兼容的上限由Belle实验，除了$Υ(2S)\to J/ψ+χ_{c1}$，其中存在一些张力之间的理论和实验。有了极化衰减宽度，我们研究了$J/ψ$的极化，结果表明它与任何非微扰参数无关。此外，根据我们的计算，由于Super B工厂的高光度，有希望测量所有过程。

英文摘要：

In this work, we study the exclusive decay of $Υ$ into $J/ψ$ in association with $η_c$ ($χ_{c0,1,2}$). The decay widths for different helicity configurations are evaluated up to QCD next-to-leading order within the nonrelativistic QCD framework. We find that the QCD corrections notably mitigate the renormalization scale dependence of the decay widths for all the processes. The branching fraction of $Υ\rightarrow J/ψ+χ_{c1}$ is obtained as $3.73^{+5.10+0.10}_{-2.06-1.19}\times 10^{-6}$, which agrees well with the Belle measurement, i.e., ${\rm Br}(Υ\rightarrow J/ψ+χ_{c1})=(3.90\pm1.21\pm0.23)\times10^{-6}$. For the other processes, our results of the branching fractions are compatible with the upper limits given by the Belle experiments, except for $Υ(2S)\to J/ψ+χ_{c1}$, where some tension exists between theory and experiment. Having the polarized decay widths, we study the $J/ψ$ polarization, which turn out to be independent of any nonperturbative parameters. Further, according to our calculation, it is promising to measure all the processes at Super B factory thanks to the high luminosity.

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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