标题： $β$衰变性质的$N=Z$核素：中子-质子配对的作用和壳模型解释 显示英文标题

标题： The $β$-decay properties of $N=Z$ nuclei: Role of neutron-proton pairing and the shell model interpretation

摘要： 我们研究了最近测量的$^{70}$Kr 通过β衰变进入$^{70}$Br 的情况，在大规模壳模型的框架下进行。与较轻的$^{62}$Ge 的$\beta$衰变相比，$^{70}$Br 中伽莫夫-泰勒（GT）跃迁强度的增强被建议为中子-质子（$np$）配对关联增加的迹象。 为了探索核中的$np$相关性，我们系统地研究了偶-偶核$A=58,62,66,$和$70$向$N=Z$奇-奇核的$\beta$衰变特性。 通过采用仅包含$J=1, T=0$和$J=0, T=1$配对矩阵元的相互作用，我们观察到，在相同的耦合强度下，配对并不一定导致 GT 强度的增强。 但随着包含$g_{9/2}$轨道，GT强度可以随着$np$配对的增加而增加，并与$g_{9/2}$轨道的增强贡献有关。我们进一步将这些结果与$fp$和$f_{5/2}pg_{9/2}$模型空间中的实际计算进行比较，以评估$f_{7/2}$和$g_{9/2}$轨道在GT强度中的贡献。 随着JUN45相互作用，与 $^{62}$Ge 的衰变相比， $^{70}$Kr 的衰变中 $1^+$状态有所增加，这是由于 $g_{9/2}$贡献的增加。 此外，我们通过修改单粒子能量和导致衰变跃迁强度的相互作用的 $T = 0$矩阵元，研究了 $np$配对对 $B_{\rm GT}$的影响。 在具有现实相互作用的计算中，我们发现累积的跃迁强度可以随着增强的$np$对配而增加。 显示英文摘要

摘要： We study the recently measured beta-decay of $^{70}$Kr into $^{70}$Br within the framework of the large-scale shell model. The enhancement in the Gamow-Teller (GT) transition strength in $^{70}$Br compared to the $\beta$-decay of the lighter $^{62}$Ge was suggested as an indication for increased neutron-proton ($np$) pairing correlation. To explore the $np$ correlations in nuclei, we systematically examined the $\beta$-decay properties of the even-even nuclei $A=58,62,66,$ and $70$ into $N=Z$ odd-odd nuclei. By employing an interaction involving solely $J=1, T=0$ and $J=0, T=1$ pairing matrix elements, we observe that the pairing does not necessarily lead to an enhancement in the GT strength for the same coupling strength. But with the inclusion of the $g_{9/2}$ orbital, the GT strength can be increased with increasing $np$ pairing in connection with the enhanced contribution from the $g_{9/2}$ orbital. We further compare those results with realistic calculations in the $fp$ and $f_{5/2}pg_{9/2}$ model space to gauge the contribution from $f_{7/2}$ and $g_{9/2}$ orbitals in the GT strengths. With the JUN45 interaction, there is an increment for the yrast $1^+$ state for the decay of $^{70}$Kr as compared to the decay of $^{62}$Ge due to increased $g_{9/2}$ contribution. Additionally, we probe the effect of $np$ pairing on $B_{\rm GT}$ by modifying the single-particle energies and the $T = 0$ matrix elements of the interaction responsible for the decay transition strength. In calculations with realistic interaction, we find that the accumulated transition strength can increase with enhanced $np$ pairing.