摘要
原子核的形变一直以来都是核结构研究中的重要内容之一,近年来,核结构效应对核反应或者重离子碰撞的影响受到越来越多的关注.本文基于极端相对论量子分子动力学(UrQMD)模型,在初始化部分考虑弹靶核的形变效应,模拟入射能量为0.4 GeV/nucleon下的^(238)U+^(238)U碰撞,探究了初始化时弹靶核的形变对于反应末态粒子集体流、π^(-)/π^(+)产额比以及核阻止本领等观测量的影响.研究发现,在形变原子核的尖对尖(长轴对长轴)碰撞中核阻止本领最大.腰对腰(短轴对短轴)的完全中心碰撞(b=0 fm)时,仍然有椭圆流产生.尖对尖碰撞给出的π^(-)/π^(+)产额比大于腰对腰碰撞给出的结果.此外,在本文所研究的体系和能量下,铀核的形变对质子椭圆流的影响大于对称能对它的影响,但中子质子椭圆流之比几乎不受初始铀核形变效应的影响.
Nuclear deformation is an important topic in the study of nuclear structure. The influence of nuclear structure on nuclear reactions and heavy-ion collisions has attracted considerable attention recently. Based on the ultra-relativistic quantum molecular dynamics(Ur QMD) model, the effect of nuclear deformation in ^(238)U+^(238)U at the beam energy of0.4 Ge V/nucleon is investigated and several observables, such as the stopping power, collective flow, and π^(-)/π^(+)yield ratio, are calculated. It is found that the stopping power obtained with tip-tip(the two nuclei with their long axes head-on)collisions is the largest among collisions with different deformations. For belly-belly(the two nuclei with their short axes head-on and long axes parallel in the reaction plane) collisions, the elliptic flow exists even for the most central collision(b=0 fm). π^(-)/π^(+)yield ratio obtained with tip-tip collision is larger than that obtained with belly-belly collision. In addition,the influence of nuclear deformation on the elliptic flow of free protons is stronger than that of nuclear symmetry energy in ^(238)U+^(238)U collisions at 0.4 Ge V/nucleon, while the elliptic flow ratio between neutrons and protons shows hardly any sensitivity to different deformations of uranium.
作者
杨佳烨
刘玲
李鹏程
王永佳
李庆峰
YANG JiaYe;LIU Ling;LI PengCheng;WANG Yong Jia;LI QingFeng(College of Physics Science and Technology,Shenyang Normal University,Shenyang 110034,China;School of Science,Huzhou University,Huzhou 313000,China;School of Nuclear Science and Technology,Lanzhou University,Lanzhou 730000,China;Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,China)
出处
《中国科学：物理学、力学、天文学》
CSCD
北大核心
2021年第11期83-91,共9页
Scientia Sinica Physica,Mechanica & Astronomica
基金
国家自然科学基金(编号:11875125,U2032145,12047568)
国家重点研发计划(编号:2020YFE0202002)
浙江省万人计划(编号:2018R52017)资助项目。
关键词
重离子碰撞
集体流
原子核形变
对称能
heavy-ion collision
collective flows
nuclear deformation
symmetry energy
