点耦合协变密度泛函理论结合复动量表象方法对奇特核的研究

Exotic nuclei research is one of the most interesting subjects in the field of nuclear physics, and the resonance plays an important role in the formation of many exotic phenomena. In this project we will develop the complex momentum representation (CMR) method in the point coupling covariant density functional theory (CDFT) framework to build the CDFT-CMR theory to calculate the energies, widths and lifetimes of resonant states. Furthermore, we introduce the BCS approximation to deal with pairing correlations in the nuclei, and establish a unified CDFT-CMR-BCS theory for describing the bound, resonances, and continuum, and we apply it to calculate the radius of the nucleus, the separation energy of the single neutron by adopting the effective interaction PC-PK2. Then we study the structures and properties of some spherical exotic nuclei. Taking Ni or Ca isotopic chain as an example, we will calculate and analysis the evolution of their structure, and then we reveal the formation mechanism of the exotic structure, which can provides a certain theoretical basis for predicting the drop lines of several nuclei and detecting new exotic phenomena in the experiment.

奇特核的研究是当前核物理领域的主要热点之一，而共振态在奇特核现象的形成中扮演重要角色。本项目拟在点耦合协变密度泛函理论（CDFT）框架下，采用复动量表象（CMR）方法研究原子核共振态，建立CDFT-CMR理论方法，计算原子核共振态能量、宽度及寿命等物理量；进一步采用BCS近似方法处理原子核中对关联效应，建立自洽统一描述束缚态、共振态和连续谱的CDFT-CMR-BCS理论方法，并采用PC-PK1有效相互势，计算若干球形奇特核的原子核半径、单中子分离能等物理量，从而探究奇特结构与性质；拟以Ni或Ca同位素链为例，计算分析其结构随中子数变化的演化规律，进而揭示奇特结构的形成机制，为预言若干原子核的滴线及实验上探测新的奇特现象提供一定的理论依据。

随着世界范围内兴起的新一代放射性核束装置以及探测设备的建造和投入运行，奇特核也被当作主要科学研究目标之一。考虑到费米面附近的共振态对奇特晕现象形成的重要性，和之前工作中复动量表象（CMR）方法研究原子核单粒子共振态的优越性和未考虑对关联效应的不足。本项目在点耦合协变密度泛函理论框架下，发展了描述球形奇特核的RMFPC-CMR理论方法，以Sn同位素链为例，研究奇特核共振态的能级结构及其演化规律。又进一步采用Bardeen-Cooper-Schrieffer(BCS)近似方法处理对关联，建立自洽统一描述束缚态、共振态和连续谱的RMFPC-CMR-BCS理论，合理地将弱束缚态和费米面附近的共振态进行耦合，探究了若干个奇特晕核。以Ce同位素链为例，得到了清晰壳层结构中束缚态和共振态的能量和宽度，计算了费米表面附近这些轨道中价核子的占据概率，并比较了每个轨道对核密度分布的贡献。在本项目的资助下，共发表9篇论文，其中被SCI收录8篇，目前在培养硕士研究生1名。