论文标题
搜索$^{\ rm c}（γ，p）$与同时检测衰减产物的反应中的$η'$绑定的核
Search for $η'$ bound nuclei in the $^{12}{\rm C}(γ,p)$ reaction with simultaneous detection of decay products
论文作者
论文摘要
我们测量了$^{12} {\ rm c}（γ，p）$反应的缺失质谱，这与来自$η'$ bound核的潜在衰减产物一致。我们标记了（$η+p $）对与$η'n\ toηn$过程相关的（核中）。在应用运动学选择减少背景后，在边界状态区域未观察到信号事件。在开头角度$ \cosθ^{ηp} _ {lab} <-0.9 $中，信号横截面的上限为90 $ \％$置信度为2.2 nb/sr。它与理论交叉部分进行了比较，理论交叉部分通过测量Quasifree $η'$生产率来抑制其归一化歧义。我们的结果表明，$η'n'n\toηn$过程和/或浅$η'$ - 核势的一小部分分支。
We measured missing mass spectrum of the $^{12}{\rm C}(γ,p)$ reaction for the first time in coincidence with potential decay products from $η'$ bound nuclei. We tagged an ($η+p$) pair associated with the $η'N\toηN$ process in a nucleus. After applying kinematical selections to reduce backgrounds, no signal events were observed in the bound-state region. An upper limit of the signal cross section in the opening angle $\cosθ^{ηp}_{lab}<-0.9$ was obtained to be 2.2 nb/sr at the 90$\%$ confidence level. It is compared with theoretical cross sections, whose normalization ambiguity is suppressed by measuring a quasifree $η'$ production rate. Our results indicate a small branching fraction of the $η'N\toηN$ process and/or a shallow $η'$-nucleus potential.
