论文标题
在$^{12} $ c中观察到的新异常支持假设X17玻色子的存在和矢量特征
New anomaly observed in $^{12}$C supports the existence and the vector character of the hypothetical X17 boson
论文作者
论文摘要
通过使用$^{11} $ b（p，$γ$）$^{12} $ c核反应，研究了$ e^+e^ - $ pairs的角度相关性，在$ 40^\circoutθ\ leq 175^\ leq 175^\ leq 175^\ leq 175^\ leq $ circ $之间的五个不同的Proton Energies之间的角度相关性。在小角度（$θ\ leq 120^\ circ $）中，可以通过具有E1和M1多极性的电磁辐射的内部对创建过程以及目标备份中的外部对创建。但是，在大于$ 120^\ circ $的角度，观察到了额外的计数过量和异常，这可以很好地考虑到先前建议的降低X17粒子的存在。我们的结果表明，X17粒子主要是在E1辐射中生成的。粒子的派生质量为$ m_ \ mathrm {x} c^2 $ = 17.03 $ \ pm 0.11（stat）\ pm 0.20（syst）$ mev。根据质量和派生的分支比率（$ b_x = 3.6（3）\ times10^{ - 6} $），这可能是相同的x17粒子，我们最近建议用来描述$^8 $ be and $^4 $ he的衰减中观察到的异常。
Employing the $^{11}$B(p,$γ$)$^{12}$C nuclear reaction, the angular correlation of $e^+e^-$ pairs was investigated in the angular range of $40^\circΘ\leq 175^\circ$ for five different proton energies between E$_p$ = 1.50 - 2.50 MeV. At small angles ($Θ\leq 120^\circ$), the results can be well interpreted by the internal pair creation process of electromagnetic radiations with E1 and M1 multipolarities and by the external pair creation in the target backing. However, at angles greater than $120^\circ$, additional count excess and anomalies were observed, which could be well accounted for by the existence of the previously suggested hypotetical X17 particle. Our results show that the X17 particle was generated mainly in E1 radiation. The derived mass of the particle is $m_\mathrm{X}c^2$=17.03$\pm 0.11 (stat) \pm 0.20 (syst)$ MeV. According to the mass, and to the derived branching ratio ($B_x=3.6(3)\times10^{-6}$), this is likely the same X17 particle, which we recently suggested for describing the anomaly observed in the decay of $^8$Be and $^4$He.
