Isospin effects of projectile fragmentation in a Boltzmann-Langevin approach

作     者：李冰 唐娜 张丰收 BingLi;Na Tang;Feng-ShouZhang

作者机构：The Key Laboratory of Beam Technology and Material Modification of Ministry of EducationCollege of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Beijing Radiation CenterBeijing 100875China Center of Theoretical Nuclear PhysicsNational Laboratory of Heavy Ion Accelerator of LanzhouLanzhou 730000China 

出 版 物：《Chinese Physics C》 (中国物理C（英文版）)

年 卷 期：2021年第45卷第8期

页      面：90-98页

核心收录：

学科分类：0709[理学-地质学] 08[工学] 0708[理学-地球物理学] 0804[工学-仪器科学与技术] 0827[工学-核科学与技术] 0703[理学-化学] 0704[理学-天文学] 0702[理学-物理学] 

基　　金：Supported by the National Natural Science Foundation of China(11635003,11025524,11161130520) National Basic Research Program of China(2010CB832903) the European Commissions 7th Framework Programme(FP7-PEOPLE-2010-IRSES)under Grant Agreement Project(269131)。 

主　　题：symmetry energy projectile fragmentation isospin-dependent Boltzmann-Langevin model isospin effect 

摘      要：The isospin effects of projectile fragmentation at intermediate energies are investigated using an isospin-dependent Boltzmann-Langevin model.The collisions of mass-symmetric reactions including 58Fe,58Ni+58Fe,and Ni at intermediate energies,in the 30 to 100 MeV/A range,are studied for different symmetry energies.Yield ratios of the isotopic,isobaric,and isotonic pairs of fragments from the intermediate-mass region using three symmetry energies are extracted as functions of the N/Z ratio of the composite systems in the entrance channel and the incident energies.It is found that the yield ratios are sensitive to symmetry energies,especially for neutron-rich systems,and the calculations using soft symmetry energy are closer to the experimental data.The isospin effect is stronger for the soft symmetry energy,owing to the competition of the repulsive Coulomb force and the symmetry energy attractive force on the proton.For the first time,the splits are presented,revealing a transition from the isospin equilibrium at lower energies to translucency at intermediate energies.The results show a degree of transparency in that intermediate mass fragments undergo a transition from dependence on the composite systems in the entrance channel to reliance on the projectile and target nuclei.