论文标题
高阶QCD校正至$υ$ nove to double Charmonia
Higher-order QCD corrections to $Υ$ decay into double charmonia
论文作者
论文摘要
在这项工作中，我们将$υ$的独家衰减与$η_c$（$χ_{C0,1,2} $）相关的$ J/ψ$。不同螺旋构型的衰减宽度在非依次QCD框架内的QCD临近序列中进行了评估。我们发现QCD校正显着减轻了所有过程的衰减宽度的重新归一化量表依赖性。 $ 3.73^{+5.10+0.10+0.10} _ { - 2.06-1.19} \ times 10^{ - 6} $获得$ 3.73^{+5.10+0.10+0.10+0.10+0.10+0.10} $的分支分支$ 3.73^^{+5.10+0.10} \ times 10^{ - 6} $，与Belle的测量很吻合，即$ 3.73+0.10} _ {+5.10+0.10} _ {+5.10+0.10} _ {+5.10+0.10} _ j/ψ+χ_ {C1}）=（3.90 \ pm1.21 \ pm0.23）\ times10^{ - 6} $。对于其他过程，我们的分支部分的结果与Belle实验给出的上限兼容，除了$υ（2s）\至J/ψ+χ_ {C1} $，其中理论和实验之间存在一些张力。具有极化的衰减宽度，我们研究了$ j/ψ$极化，事实证明它与任何非扰动参数无关。此外，根据我们的计算，由于高光度，可以衡量超级B工厂的所有过程。
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.
