Ravlić Ante, Yüksel Esra, Nikšić Tamara, Paar Nils
Department of Physics, Faculty of Science, University of Zagreb, Bijenička c. 32, 10000, Zagreb, Croatia.
Department of Physics, University of Surrey, Guildford, Surrey, GU2 7XH, UK.
Nat Commun. 2023 Aug 10;14(1):4834. doi: 10.1038/s41467-023-40613-2.
Properties of nuclei in hot stellar environments such as supernovae or neutron star mergers are largely unexplored. Since it is poorly understood how many protons and neutrons can be bound together in hot nuclei, we investigate the limits of nuclear existence (drip lines) at finite temperature. Here, we present mapping of nuclear drip lines at temperatures up to around 20 billion kelvins using the relativistic energy density functional theory (REDF), including treatment of thermal scattering of nucleons in the continuum. With extensive computational effort, the drip lines are determined using several REDFs with different underlying interactions, demonstrating considerable alterations of the neutron drip line with temperature increase, especially near the magic numbers. At temperatures T ≲ 12 billion kelvins, the interplay between the properties of nuclear effective interaction, pairing, and temperature effects determines the nuclear binding. At higher temperatures, we find a surprizing result that the total number of bound nuclei increases with temperature due to thermal shell quenching. Our findings provide insight into nuclear landscape for hot nuclei, revealing that the nuclear drip lines should be viewed as limits that change dynamically with temperature.
在超新星或中子星合并等炽热恒星环境中，原子核的性质在很大程度上尚未得到探索。由于人们对在热原子核中能结合多少质子和中子了解甚少，我们研究了有限温度下原子核存在的极限（滴线）。在此，我们利用相对论能量密度泛函理论（REDF）呈现了温度高达约200亿开尔文时的原子核滴线图谱，其中包括对连续介质中核子热散射的处理。通过大量的计算工作，使用具有不同基本相互作用的几种REDF确定了滴线，结果表明随着温度升高，中子滴线有相当大的变化，尤其是在幻数附近。在温度T≲120亿开尔文时，核有效相互作用、配对和温度效应的性质之间的相互作用决定了核束缚。在更高温度下，我们发现了一个惊人的结果，即由于热壳层猝灭，束缚原子核的总数随温度增加。我们的研究结果为热原子核的核图景提供了见解，揭示了原子核滴线应被视为随温度动态变化的极限。
