发表机构
Shanghai Advanced Research Institute, Chinese Academy of Sciences; Shanghai Institute of Applied Physics, Chinese Academy of Sciences; University of Chinese Academy of Sciences; Institute of Nuclear Science and Technology, Henan Academy of Sciences; Centre of Theoretical Physics, College of Physics, Henan Normal University; Shanghai Research Center for Theoretical Nuclear Physics, NSFC and Fudan University; Key Laboratory of Nuclear Physics and Ion-beam Application (MOE), Institute of Modern Physics, Fudan University（上海高等研究院，中国科学院; 上海应用物理研究所，中国科学院; 中国科学院大学; 河南省科学院核科学技术研究所; 河南师范大学物理学院理论物理中心; 国家自然科学基金委与复旦大学理论核物理上海研究中心; 复旦大学现代物理研究所核物理与离子束应用教育部重点实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究识别出核固液相变的信号，通过成对距离概率密度函数揭示其空间特征，为核结构、相图及天体物理研究提供了新见解。
AI 中文摘要
核相图仍是基础难题，揭示团簇自由度如何随温度和能量演化，对理解团簇、核子及核天体物理间的有趣交叉至关重要。一种新的一阶相变——核固液相变（SLPT），在低能重离子碰撞中从核子自由度自发产生。SLPT的清晰信号包括：较小系统（如$^{12}\ ext{C} + ^{12}\ ext{C}$和$^{16}\ ext{O} + ^{12}\ ext{C}$）中存在负热容区域，较大系统（如$^{28}\ ext{Si} + ^{12}\ ext{C}$和$^{40}\ ext{Ca} + ^{12}\ ext{C}$）中存在量热平台，以及碎片种类数和信息熵的显著行为。此外，成对距离概率密度函数提供了熔化的直接空间指纹：长程晶态α团簇峰在转变温度以上消失，被类液体分布取代。这种新相变统一了有限组分的多体动力学，从纳米级团簇延伸至核系统。除推进核结构和相图外，这些见解对天体物理具有深远意义，尤其通过超新星中的核团簇溶解，将结构演化与天体物理相变关联起来。
英文摘要
The nuclear phase diagram remains a fundamental challenge, where uncovering how the cluster degree of freedom evolves with temperature and energy is essential to understand the intriguing crossover between cluster, nucleon, and nuclear astrophysics. A new first-order phase transition, the nuclear solid-liquid phase transition (SLPT), emerges spontaneously from nucleonic degrees of freedom in low-energy heavy-ion collisions. Clear signals of the SLPT are identified as a region of negative heat capacity in smaller systems (e.g., $^{12}\text{C} + ^{12}\text{C}$ and $^{16}\text{O} + ^{12}\text{C}$) and a caloric plateau in larger systems (e.g., $^{28}\text{Si} + ^{12}\text{C}$ and $^{40}\text{Ca} + ^{12}\text{C}$), along with prominent behaviors in the number of fragment species and information entropy. Moreover, the pairwise distance probability density function provides a direct spatial fingerprint of the melting, where long-range crystalline $α$-cluster peaks vanish above the transition temperature, giving way to a liquid-like distribution. This new phase transition unifies the many-body dynamics of finite constituents, extending from nanoscale clusters to nuclear systems. Beyond advancing nuclear structure and phase diagrams, these insights offer profound implications for astrophysics, notably linking structural evolution to astrophysical phase transitions via nuclear cluster dissolution in supernovae.
