论文标题
UPSILON（NS）辐射衰减到S波和P波charmon
Radiative decays of Upsilon(nS) into S-wave and P-wave charmonium
论文作者
论文摘要
在Belle的辐射衰减的最新测量中，我们使用了非同性QCD分解理论，并计算底部辐射型腐烂的分支分支机构，以$∂（1s）$ to $υ（1s）$至$χ_{C1} $的动机。 $υ（ns）\toχ_{cj}+γ$。我们系统地研究了底部辐射衰变的分支分数。与先前的计算相比，我们获得了衰减宽度的分析表达，并考虑了颜色贡献的贡献。对于$υ（ns）\至η_c（ns）+γ$，还可以获得相对论校正。通过计算，$υ（1s）\toχ_{C1}+γ$的理论预测仍然小于最近的Belle测量。进一步的理论工作和实验分析对于了解Upsilon衰减中的$χ_{C1} $生产机制是必要的。
Motivated by very recent measurement of the radiative decays of $Υ(1S)$ to $χ_{c1}$ at Belle, we use the nonrelativistic QCD factorization theory and calculate the branching fractions of the radiative decays of bottomonium into S-wave and P-wave charmonium, i.e. $Υ(nS) \to η_c(nS)+γ$ and $Υ(nS)\to χ_{cJ}+γ$. We systematically studied the branching fractions of the radiative decays of bottomonium into charmonium. Compared to the previous calculation, we obtained the analytical expression for the decay widths and considered the color-octet contributions. For $Υ(nS) \to η_c(nS)+γ$, the relativistic corrections are also obtained. Through the calculation, the theoretical prediction for $Υ(1S)\toχ_{c1}+γ$ is still smaller than the recent Belle measurement. Further theoretical work and experimental analysis are necessary to understand the $χ_{c1}$ production mechanism in upsilon decays.
