论文标题
中子丰富的$^8 $ He中的软偶极共振
Soft dipole resonance in neutron-rich $^8$He
论文作者
论文摘要
在中子丰富的$^8 $ HE中，我们研究了软偶极子共振，该共振被认为是四个价中子的偶极子振荡，而对$^4 $ HE的核心，其对低能电动偶极偶极强度的效果具有$^4 $^4 $ He $ He+N $ n $ N $+N $ N $ N $ N $ N $ N $ N $+N $ N $ N $+N $ fiff fiff fiff fiff fiff fiff fiff fiffer five-ford-fody cluster模型。这项工作是对早期字母的扩展研究。 Myo和K.Katō，物理。 Rev. C106，L021302（2022）]。使用复杂的缩放法和偶极强度，根据复杂的能量特征值获得了五体未结合的$ 1^ - $ $^8 $的状态。在激发能的20 meV以下的偶极强度中证实了两种主要的激发模式。低于10 MEV的优势被$^7 $ HE+$ n $ channel所耗尽，后者依次衰减到$^6 $ he+$ n $+$ n $。在10 MEV以上，优势是由四个中子（$ 4N $）的软偶极模式产生的，反对$^4 $ He Core。我们通过仔细搜索共振极，进一步探讨了该状态的软偶极子共振的可能性，并最终以14 MeV的激发能和21 MeV的衰减宽度预测相应的共振。柔软的偶极子共振在相对运动的$^4 $ HE核心和$ 4N $之间的相对运动中耗尽了一半的偶极强度。
In neutron-rich $^8$He, we study the soft dipole resonance, which is regarded as a dipole oscillation of four valence neutrons against the $^4$He core, and its effect on the low-energy electric dipole strength with a $^4$He+$n$+$n$+$n$+$n$ five-body cluster model. This work is an extended study of an earlier letter [T. Myo and K. Katō, Phys. Rev. C106, L021302 (2022)]. The five-body unbound $1^-$ states of $^8$He are obtained with the complex energy eigenvalues by using the complex scaling method and the dipole strength is calculated in terms of the complex-scaled Green's function. Two kinds of the dominant excitation modes are confirmed in the dipole strength below 20 MeV of the excitation energy. The strengths below 10 MeV are exhausted by the $^7$He+$n$ channel, which sequentially decays to $^6$He+$n$+$n$. Above 10 MeV, the strengths arise from the soft dipole mode of four neutrons ($4n$) oscillating against the $^4$He core. We further explore the possibility of the soft dipole resonance for this state by carefully searching for the resonance pole and finally predict the corresponding resonance with the excitation energy of 14 MeV and the decay width of 21 MeV. The soft dipole resonance exhausts about half of the dipole strength in the relative motion between the $^4$He core and $4n$.
