论文标题
在$ j/ψ\rightarrowγπ^0η^{\ prime} $中搜索中间共振和深色仪表玻色子
Search for intermediate resonances and dark gauge bosons in $J/ψ\rightarrowγπ^0η^{\prime}$
论文作者
论文摘要
我们使用$（1310.6 \ pm 7.0）\ times〜10^6〜j/ψ$事件的样品报告了对衰减$ j/ψ\rightArrowγπ^0η^0η^{\ prime} $的分析。我们搜索cp-violating过程$η_c\rightarrowπ^0η^{\ prime} $和一个深色的玻色子$ u'o' $'$ in $ j/ψ\ rightarrow u^{\ prime} \ prime}η^{\ prime}在$π^0η^{\ prime} $不变质量频谱中没有观察到$η_{C} $信号的证据，并且分支分数的上限确定为90 \％置信度的$ 7.2 \ times 〜10^{-5} $。我们也没有发现$ u'$生产的证据，也没有将上限设置为产品分支分支的90 \％置信度，$ \ nathcal {b}（j/ψ\ rightarrow u^{\ prime}η^{\ prime} \ prime} \ prime}） $（0.8-6.5）\ times 10^{ - 7} $ for 0.2 $ \ leq m_ {u^{\ prime}}} \ leq 2.1 $ gev $/c^{2} $。此外，我们研究了$ j/ψ\rightarrowΩη^{\ prime} $，以及$ω\rightarrowγπ^0 $。 $ j/ψ\rightArrowωη^{\ prime} $的分支部分被发现为$（1.87 \ pm0.09 \ pm0.12）\ times 10^{ - 4} $，第一个不确定性是统计是统计的，第二个不确定性是系统性的，并具有1.4以前的bess cormity of 1.4 iiii iiiii iii ii ii ii ii ii ii ii ii ii ii ii ii is percient。
We report on an analysis of the decay $J/ψ\rightarrowγπ^0η^{\prime}$ using a sample of $(1310.6 \pm 7.0) \times ~10^6~ J/ψ$ events collected with the BESIII detector. We search for the CP-violating process $η_c\rightarrowπ^0η^{\prime}$ and a dark gauge boson $U'$ in $J/ψ\rightarrow U^{\prime}η^{\prime},~U^{\prime}\rightarrowγπ^0,~π^0\rightarrowγγ$. No evidence of an $η_{c}$ signal is observed in the $π^0η^{\prime}$ invariant-mass spectrum and the upper limit of the branching fraction is determined to be $7.2 \times~10^{-5}$ at the 90\% confidence level. We also find no evidence of $U'$ production and set upper limits at the 90\% confidence level on the product branching fraction $\mathcal{B}(J/ψ\rightarrow U^{\prime} η^{\prime}) \times \mathcal{B}(U^{\prime} \rightarrow π^{0} γ)$ in the range between $(0.8 - 6.5)\times 10^{-7}$ for 0.2 $\leq m_{U^{\prime}} \leq 2.1 $GeV$/c^{2}$. In addition, we study the process $J/ψ\rightarrowωη^{\prime}$ with $ω\rightarrowγπ^0$. The branching fraction of $J/ψ\rightarrowωη^{\prime}$ is found to be $(1.87\pm0.09\pm0.12) \times 10^{-4}$, where the first uncertainty is statistical and the second is systematic, with a precision that is improved by a factor of 1.4 over the previously published BESIII measurement.
