论文标题
通过$ e^+e^ - \ to k^+k^ - j/ψ$确认新的高charmon $ψ（4500）$的存在
Confirming the existence of a new higher charmonium $ψ(4500)$ by the newly released data of $e^+e^- \to K^+K^- J/ψ$
论文作者
论文摘要
最近，BESIII合作发布了$ e^+e^ - \ to k^+k^ - j/ψ$的出生横截面，其中首次观察到新的向量增强结构$ y（4500）$。 $ Y（4500）$共振结构的质量与我们以前的预测符合$ 5S $ -4D $搅拌charmonium候选$ψ（4500）$的预测，而测得的宽度为$2σ$，大于理论估计。在这项工作中，我们通过引入两个理论上预测的Charmonat状态$ψ（4220）$和$ψ（4500）$作为中间共振，并发现此宽度偏差问题可以分辨出来。同时，我们发现包含两个已建立的charmonium国家$ψ（4160）$和$ψ（4415）$可以进一步提高拟合质量，四套与$γ_{e^+e^ - } \ Mathcal {b}（b}（b}（ψ\ tok^to K^+k^+k^+k^ - j^-j/ψ））的解决方案截然不同。 In order to better identify the properties of the $Y(4500)$, we calculated the charmonium hadronic transition to final states $K^+K^- J/ψ$ within the charmed meson loop mechanism, where the fitted branching ratio of $ψ(4500) \to K^+K^- J/ψ$ can be well explained by the theoretical calculation, further supporting the new enhancement structure around 4.5 GeV as a我们预测的更高的charmonuim $ψ（4500）$。最后，我们还讨论了$ e^+e^ - \ in $ e^+e^ - \ in K^+k^ - j/ψ$中另一个预测的charmonium候选$ψ（4380）$的可能信号。这些研究结果应该是构建Charmonium家族并彻底解决Charmonium型$ y $问题的重要一步。
Recently, the BESIII Collaboration published the Born cross section of $e^+e^- \to K^+K^- J/ψ$, in which a new vector enhancement structure $Y(4500)$ was observed for the first time. The mass of the $Y(4500)$ resonance structure is in good agreement with our previous prediction for a $5S$-$4D$ mixing charmonium candidate $ψ(4500)$, while the measured width is $2σ$ larger than the theoretical estimate. In this work, we reanalyzed the cross section of $e^+e^- \to K^+K^- J/ψ$ by introducing two theoretically predicted charmonium states $ψ(4220)$ and $ψ(4500)$ as intermediate resonances, and found that this width deviation problem can be resolved. Meanwhile, we found that the inclusion of two established charmonium states $ψ(4160)$ and $ψ(4415)$ can further improve the fit quality, with four sets of widely different solutions to $Γ_{e^+e^-} \mathcal{B}(ψ\to K^+K^- J/ψ)$. In order to better identify the properties of the $Y(4500)$, we calculated the charmonium hadronic transition to final states $K^+K^- J/ψ$ within the charmed meson loop mechanism, where the fitted branching ratio of $ψ(4500) \to K^+K^- J/ψ$ can be well explained by the theoretical calculation, further supporting the new enhancement structure around 4.5 GeV as a higher charmonium $ψ(4500)$ that we predicted. Finally, we also discussed the possible signal of another predicted charmonium candidate $ψ(4380)$ in $e^+e^- \to K^+K^- J/ψ$. These research results should be an important step in constructing the charmonium family and thoroughly solving the charmoniumlike $Y$ problem.
