Abstract The Jacobi-type transitions (JTTs) in nuclei and their connections with excite-state quantum phase transitions (ESQPTs) have been investigated within the framework of the interacting boson model (IBM) by both the semiclassical analysis and quantal calculations. The results indicates that the quadrupole deformation of a transitional system may change from γ rigid to γ soft as the angular momentum increase. This change may in turn drive the JTTs to occur around the saddle point of the corresponding classical potential, where the precursors of ESQPT can be also identified even for a realistic boson number. A further comparison between the experimental data and the model predictions confirms that the JTT phenomena may widely occur in the rare-earth isotopes associated with the 1st-order quantum phase transitions.

中文翻译：

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关于有限核中雅可比型跃迁的注记

摘要 在相互作用玻色子模型 (IBM) 的框架内，通过半经典分析和量子计算研究了原子核中的雅可比型跃迁 (JTT) 及其与激发态量子相变 (ESQPT) 的联系。结果表明，随着角动量的增加，过渡系统的四极变形可能会从 γ 刚性变为 γ 软。这种变化可能反过来促使 JTT 发生在相应经典势的鞍点附近，即使对于现实的玻色子数，也可以识别出 ESQPT 的前体。实验数据与模型预测的进一步比较证实，JTT 现象可能广泛发生在与一阶量子相变相关的稀土同位素中。