Isospin effects on intermediate mass fragments at intermediate energy-heavy ion collisions  

作　　者：Li Li Fang-Yuan Wang Ying-Xun Zhang 

机构地区：[1]China Institute of Atomic Energy,P.O.Box 275(18),Beijing 102413,China [2]Department of Physics and Technology,Guangxi Normal University,Guilin 540101,China

出　　处：《Nuclear Science and Techniques》2022年第5期68-77,共10页核技术（英文）

基　　金：supported by the National Natural Science Foundation of China(Nos.11875323,11705163,11790320,11790323,and11961141003);the National Key R&D Program of China(No.2018YFA0404404);the Continuous Basic Scientific Research Project(Nos.WDJC-2019-13,BJ20002501);funding from the China Institute of Atomic Energy and the Leading Innovation Project of CNNC(Nos.LC192209000701 and LC202309000201)。

摘　　要：In this study,we investigated the isospin properties of intermediate mass fragments(IMFs)for the central collisions of^(112,124)Sn+^(112,124)Sn at a beam energy of50 MeV per nucleon using an improved quantum molecular dynamics model(ImQMD)coupled with a sequential decay model(GEMINI).Three observables were analyzed:(1)the average center-of-mass kinetic energy per nucleon<Ec.m./A>of fragments as a function of their charge number Z;(2)the average neutron number to proton number ratio(<N>/Z)of fragments with a given charge number Z as a function of their center-of-mass kinetic energy per nucleon(Ec.m./A);and(3)the average total neutron number to total proton number ratio(ΣN/ΣZ)and double ratio(DR(N/Z))of IMFs with Z=3-8 as a function of their center-of-mass kinetic energy per nucleon Ec.m./A.Our calculations revealed that the sensitivity of the isospin properties of IMFs relative to the stiffness of the symmetry energy remains even after sequential decay.By comparing the calculations ofΣN/ΣZ and DR(N/Z)with the data,it was found that the soft symmetry energy,i.e.,γ=0.5,is favored.

关 键 词：Symmetryenergy Intermediatemass fragments Isospin effects 

分 类 号：O571.6[理学—粒子物理与原子核物理]