中子皮结构及其在核反应中的效应

Neutron skin thickness and its effects in nuclear reactions

中子皮是不稳定原子核中存在的一种奇特结构,在核反应过程中会产生各种效应。不同理论模型研究发现,中子皮厚度会影响核-核碰撞中的中子擦去截面、轻粒子产额比、重碎片产额比、光子产生截面等物理量,也与原子核的集团结构、表面宽度、温度等存在密切关系。在高能重离子碰撞中研究发现,中子皮同样存在明确的效应。实验上,基于放射性核束装置可以产生具有中子皮结构的不稳定核,通过测量其与稳定核发生反应后与中子皮敏感的观测量,能提取或确定中子皮厚度。结合核理论模型,可以进一步约束非对称核物质的状态方程及核天体的相关性质。

The physics of radioactive nuclear beams is one of the frontiers of nuclear physics.New phenomena and physics appear in exotic nuclei far from theβ-stability line.The neutron skin is an exotic phenomena in unstable nuclei and is closely correlated with the properties of the equation of state(EOS)of asymmetric nuclear matter and neutron stars.This study sought to examine previous studies on the effect of the neutron skin on nuclei-nuclei collisions to identify good observables for determining the neutron skin thickness,which could in turn be used to investigate the EOS of asymmetric nuclear matter.Various theoretical models are used to study the effect of neutron skin in nuclei-nuclei collisions.The statistical abrasion-ablation(SAA)and isospin-dependent quantum molecular dynamics(IQMD)models are used to study the neutron abrasion cross-section,neutron/proton ratio,and t/3He ratios.A nuclear structure model is used to investigate the relation between the neutron skin andα-cluster formation,αdecay,nuclear surface,and nuclear temperature.Strong correlations have been found between the neutron skin thickness and neutron abrasion cross-section,neutron/proton ratio,and t/3He ratios,photo production,and other quantities.By measuring quantities that have a strong correlation with the neutron skin,the skin thickness can be obtained.The EOS of asymmetric nuclear matter and properties of neutron stars can be studied or constrained by using the obtained neutron skin data.Further investigations are necessary for determining observables that are useful for determining the neutron skin thickness from experimental measurements.