Nuclear shape coexistence is the phenomenon in which distinct shapes occur within the same nucleus and at a similar energy. In this work, we provide an overview of the experimental investigations of shape coexistence, focusing on those regions of the nuclear chart that have been the most actively investigated within the past decade. In particular, we focus on coexistence phenomena at low angular momentum and on the new experimental information, placed within the context of previous results. We first give a summary of the experimental signatures that can be used for assessing shape coexistence, and then discuss the evidence for shape coexistence from experimental results, with particular attention paid to regions where its presence has been suggested along isotopic or isotonic chains, and in regions where “islands” of such structures have been proposed. We conclude with an overview, with an emphasis on the emerging regions where indications for multiple shape coexistence exist.

核形状共存是在同一核内以相似能量出现不同形状的现象。在这项工作中，我们概述了形状共存的实验研究，重点关注过去十年中研究最活跃的核图区域。特别是，我们关注低角动量下的共存现象和新的实验信息，放在先前结果的背景下。我们首先总结了可用于评估形状共存的实验特征，然后从实验结果讨论形状共存的证据，特别注意沿同位素或等渗链表明存在形状共存的区域，以及在已提出此类结构的“岛屿”的地区。我们以概述结束，重点关注存在多种形状共存迹象的新兴地区。