Higher-Order QCD Corrections to ϒ Decay into Double Charmonia.
Higher-Order QCD Corrections to ϒ Decay into Double Charmonia.
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DOI：
10.1103/physrevlett.129.112002
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发表时间：
2022-05
影响因子：
8.6
通讯作者：
Yu-Dong Zhang;Wen-Long Sang;Hong-Fei Zhang
中科院分区：
文献类型：
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作者：
Yu-Dong Zhang;Wen-Long Sang;Hong-Fei Zhang
在这封信中，我们研究了与η_{c}相关的J/ψ的专属衰变（χ_{c,1,2}）。在非相对论性QCD框架下，计算了不同螺旋构型的衰减宽度，直至QCD的次领先阶。我们发现，QCD校正显著减轻了所有过程中衰减宽度的重整化尺度依赖性。的分支分数ϒ→J /ψ+χ_ {c1}获得3.73 _{-2.06 - -1.19}^{+ 5.10 + 0.10}×10 ^{6},同意与美女的测量,例如,Br(ϒ→J /ψ+χ_ {c1}) =(3.90±1.21±0.23)×10 ^{6}。对于其他过程，我们的分支分数结果与Belle实验给出的上限是一致的，除了y （2S）→J/ψ+χ_{c1}，其中理论和实验之间存在一些矛盾。有了极化衰减宽度，我们研究了J/ψ的极化，它与任何非摄动参数无关。此外，根据我们的计算，由于超级B工厂的高亮度，有希望测量所有过程。
In this Letter, 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→J/ψ+χ_{c1} is obtained as 3.73_{-2.06-1.19}^{+5.10+0.10}×10^{-6}, which agrees well with the Belle measurement, i.e., Br(ϒ→J/ψ+χ_{c1})=(3.90±1.21±0.23)×10^{-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)→J/ψ+χ_{c1}, where some tension exists between theory and experiment. Having the polarized decay widths, we study the J/ψ polarization, which turns 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.