Institute for Nuclear Theory, University of Washington, Seattle, Washington 98195, USA.
JINA-CEE, Michigan State University, East Lansing, Michigan 48824, USA.
Phys Rev Lett. 2019 Nov 15;123(20):202501. doi: 10.1103/PhysRevLett.123.202501.
The nuclear response theory for charge-exchange modes in the relativistic particle-vibration coupling approach is extended to include for the first time particle-vibration coupling effects in the ground state of the parent nucleus. In a framework based on the effective meson-nucleon Lagrangian, we investigate the role of such complex ground-state correlations in the description of Gamow-Teller transitions in ^{90}Zr in both (p, n) and (n, p) channels. The particle-vibration coupling effects are calculated without introducing new parameters. We find that this new correlation mechanism is fully responsible for the appearance of the strength in the (n, p) branch. Comparison of our results to the available experimental data shows a very good agreement up to excitation energies beyond the giant resonance region when taking into account a phenomenological admixture of the isovector spin monopole transitions. The parent-daughter binding-energy differences are also greatly improved by the inclusion of the new correlations.
在相对论粒子-振动耦合方法中，对电荷交换模式的核反应理论进行了扩展，首次将核基态的粒子-振动耦合效应纳入其中。在基于有效介子-核拉格朗日的框架中，我们研究了这种复杂的基态关联在描述^{90}Zr 中(p,n)和(n,p)通道中的 Gamow-Teller 跃迁中的作用。粒子-振动耦合效应是在不引入新参数的情况下计算的。我们发现，这种新的关联机制完全负责(n,p)分支中强度的出现。将我们的结果与现有的实验数据进行比较表明，当考虑到同位旋单极跃迁的唯象混合时，在考虑到巨共振区域之外的激发能时，这种新的关联机制与实验数据非常吻合。通过包括新的相关性，还大大改善了母-子结合能差异。
