论文标题
在两种中子旋转核中低洼激励的电偶极响应$ \ boldsymbol {^{29}} $ f
Electric dipole response of low-lying excitations in the two-neutron halo nucleus $\boldsymbol{^{29}}$F
论文作者
论文摘要
最近通过敲除和互动横截面测量值研究了中子丰富的$^{28,29} $ f同位素。 $^{29} $ F中的$ 2N $ HARO已与$ PF $ Intuder配置的占用链接。我们调查了$^{29} $ f的界限和连续状态，重点介绍了$ e1 $的低洼激发响应以及偶极耦合对核反应的影响。 $^{29} \ text {f} $（$^{27} \ text {f}+n+n $）波函数是在超透明谐波形式主义中构建的，并且使用Glauber理论计算反应横截面。使用分析基础，以伪静态方法描述了连续状态和$ b（E1）$过渡概率。在CDCC计算中使用了相应的结构形式因子来描述低能散射。 $^{28} $ f中的奇偶校验反转导致$^{29} $ f地基状态，其特征为$（p_ {3/2}）^2 $入侵者组件的57.5％，强劲的dineutron配置，强大的dineutron配置，并且与核心半径相对于$δr= 0.20 $ fm的核心半径增加。在240 MeV/核子下，碳靶的Glauber模型计算提供了1370 MB的总反应横截面，与最新数据一致。该模型还产生与四极激发相对应的几乎没有结合的激发态。 $ b（E1）$计算连续体的计算产生的总强度为1.59 E $^2 $ fm $^2 $最高6 meV，而$ e1 $的分销的共振在$ \ $ \ $ 0.85 mev。结果使用标准的壳牌模型订单，$^{28} $ f导致$ b（e1）$分布的大幅减少。 $^{29} \ text {f}+^{120} \ text {sn} $周围的四体CDCC计算以偶极耦合为主，这完全取消了弹性交叉部分中的菲涅尔峰。这些结果与两次中子光环一致，并可能指导未来的实验活动。
The neutron-rich $^{28,29}$F isotopes have been recently studied via knockout and interaction cross-section measurements. The $2n$ halo in $^{29}$F has been linked to the occupancy of $pf$ intruder configurations. We investigate bound and continuum states in $^{29}$F, focusing on the $E1$ response of low-lying excitations and the effect of dipole couplings on nuclear reactions. $^{29}\text{F}$ ($^{27}\text{F}+n+n$) wave functions are built within the hyperspherical harmonics formalism, and reaction cross sections are calculated using the Glauber theory. Continuum states and $B(E1)$ transition probabilities are described in a pseudostate approach using the analytical THO basis. The corresponding structure form factors are used in CDCC calculations to describe low-energy scattering. Parity inversion in $^{28}$F leads to a $^{29}$F ground state characterized by 57.5% of $(p_{3/2})^2$ intruder components, a strong dineutron configuration, and an increase of the matter radius with respect to the core radius of $ΔR=0.20$ fm. Glauber-model calculations for a carbon target at 240 MeV/nucleon provide a total reaction cross section of 1370 mb, in agreement with recent data. The model produces also a barely bound excited state corresponding to a quadrupole excitation. $B(E1)$ calculations into the continuum yield a total strength of 1.59 e$^2$fm$^2$ up to 6 MeV, and the $E1$ distribution exhibits a resonance at $\approx$ 0.85 MeV. Results using a standard shell-model order for $^{28}$F lead to a considerable reduction of the $B(E1)$ distribution. The four-body CDCC calculations for $^{29}\text{F}+^{120}\text{Sn}$ around the Coulomb barrier are dominated by dipole couplings, which totally cancel the Fresnel peak in the elastic cross section. These results are consistent with a two-neutron halo and may guide future experimental campaigns.
