This review presents the current status of experimental evidence for the occurrence of reflection-asymmetric or ‘pear’ shapes in atomic nuclei, which arises from the presence of strong octupole correlations in the nucleon–nucleon interactions. The behaviour of energy levels and electric octupole transition moments is reviewed, with particular emphasis on recent measurements. The relevance of nuclear pear shapes to measurements of fundamental interactions is also discussed.

中文翻译：

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梨形原子核

这篇综述介绍了原子核中出现反射不对称或“梨形”形状的实验证据的现状，这是由于核子-核子相互作用中存在强八极相关性而引起的。回顾了能级和电八极跃迁矩的行为，特别强调了最近的测量。还讨论了核梨形与基本相互作用测量的相关性。