arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1208.0900hep-ex
收藏

$Υ(1S)$和$Υ(2S)$辐射衰变中粲偶素和类粲偶素态的研究

Search for charmonium and charmonium-like states in $Υ(1S)$ and $Υ(2S)$ radiative decays

C. P. Shen

备注：
8 pages, 3 figures, 1 table; to appear in the proceedings of The 5th International Workshop on Charm Physics (Charm 2012)
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

使用样本的1.02亿$Υ(1S)$和1.58亿$Υ(2S)$事件样本收集的Belle检测器，我们报告的第一次搜索电荷奇偶偶粲和粲类状态的$Υ(1S)$和$Υ(2S)$辐射衰变。未观察到显著的$χ_{cJ}$或$η_c$信号，90% C. L.获得了对$\BR(Υ(nS)\to γχ_{cJ})$（$n=1,2$和$J=1,2,3$）的限制。没有观察到任何charmonium样状态的显著信号。在90% C. L下获得产品支化分数限度$\BR(Υ(nS)\to γX(3872))$ $\BR(X(3872)\toπ^+π^-\jpsi)$、$\BR(Υ(nS)\to γX(3872))$ $\BR(X(3872)\toπ^+π^-π^0 \jpsi)$、$\BR(Υ(nS)\to γX(3915))$ $\BR(X(3915)\toω\jpsi)$和$\BR$ $(Υ(1S)\to γY(4140))\BR(Y(4140)\to ϕ\jpsi)$（$n=1,2$）。同时测定了$\BR(Υ(2S) \to γX(4350))\BR(X(4350)\toϕ\jpsi))$在90% C. L.此外，没有证据表明，激发charmonium状态低于4.8 GeV/ $c^2$。

英文摘要：

Using samples of 102 million $Υ(1S)$ and 158 million $Υ(2S)$ event samples collected with the Belle detector, we report on the first search for charge-parity-even charmonium and charmonium-like states in $Υ(1S)$ and $Υ(2S)$ radiative decays. No significant $χ_{cJ}$ or $η_c$ signal is observed and 90% C.L. limits on $\BR(Υ(nS)\to γχ_{cJ})$ ($n=1,2$ and $J=1,2,3$) are obtained. No significant signal of any charmonium-like state is observed. The product branching fraction limits $\BR(Υ(nS)\to γX(3872))$ $\BR(X(3872)\toπ^+π^-\jpsi)$, $\BR(Υ(nS)\to γX(3872))$ $\BR(X(3872)\toπ^+π^-π^0 \jpsi)$, $\BR(Υ(nS)\to γX(3915))$ $\BR(X(3915)\toω\jpsi)$, and $\BR$ $(Υ(1S)\to γY(4140))\BR(Y(4140)\to ϕ\jpsi)$ ($n=1,2$) are obtained at the 90% C.L. At the same time, $\BR(Υ(2S) \to γX(4350))\BR(X(4350)\toϕ\jpsi))$ is also determined at the 90% C.L. Furthermore, no evidence is found for excited charmonium states below 4.8 GeV/$c^2$.

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。

↑