The neutron-rich barium nuclei have been the subject of intense interest due to the enhanced octupole correlations they are predicted to exhibit. The observation of enhanced octupole collectivity in Ba144,146 as measured in sub-barrier Coulomb excitation, consistent with static octupole deformation, has further heightened this interest. In the present work, these studies are extended to the neighboring odd-mass Ba143 to investigate the interplay between single-particle and collective octupole degrees of freedom. A new measurement of the first 92−-state lifetime is also presented. Reflection-Asymmetric Triaxial Particle Rotor Model calculations indicate that the negative-parity bands in Ba143 can be understood as a decoupled structure of νh9/2 parentage, while the positive-parity bands are built on a decoupled octupole phonon. No evidence for E3 excitation is observed in this work, but an upper limit is placed on the E3 matrix element to the lowest octupole band.

中文翻译：

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Ba143 中的四极和八极集体

由于预计它们会表现出增强的八极相关性，富含中子的钡核一直是人们非常感兴趣的主题。观察到 Ba144,146 中增强的八极集合性，如在子势垒库仑激发中测量的，与静态八极变形一致，进一步提高了这种兴趣。在目前的工作中，这些研究扩展到邻近的奇质量 Ba143，以研究单粒子和集体八极自由度之间的相互作用。还介绍了第一个 92 态寿命的新测量。反射-非对称三轴粒子转子模型计算表明，Ba143 中的负奇偶带可以理解为 νh9/2 parentage 的去耦结构，而正奇偶带建立在去耦八极声子上。