It is investigated whether the “X17 puzzle” might be explained by a nuclear decay chain and a conversion of the two resulting highly energetic γs into an electron-positron pair. It is found that the corresponding kinematics fits perfectly to the experimental result. Also the conversion rates of this process are reasonable. However, the assumed nuclear chain reaction is not favored in the established nuclear models and no explanation for the isospin structure of the signal can be given. Thus, it has to be concluded that the process studied in this paper does not give a completely satisfying explanation of the “X17 puzzle”.

中文翻译：

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X17：是新的力量，还是存在艰难的γ  +  γ过程的证据？

研究“ X17难题”是否可能由核衰变链和两个由此产生的高能γ转换成电子-正电子对来解释。发现相应的运动学完全符合实验结果。此过程的转化率也是合理的。但是，假定的核链反应在建立的核模型中不受欢迎，并且无法给出信号的同位旋结构的解释。因此，必须得出结论，本文研究的过程不能完全令人满意地解释“ X17难题”。