Temperature and symmetry energy of neutron-rich fragments in the 1A GeV^(124,136)Xe+Pb reactions  

作　　者：MA Chunwang QIAO Chunyuan WANG Shanshan LU Fangmei CHEN Li GUO Meiting 

机构地区：[1]Institute of Particle and Nuclear Physics,Henan Normal University

出　　处：《Nuclear Science and Techniques》2013年第5期50-53,共4页核技术（英文）

基　　金：Supported by National Natural Science Foundation of China(NSFC) Projects (No.10905017);the Program for Science&Technology Innovation Talents in Universities of Henan Province(No.2013HASTIT046);the Young Teacher Project in Henan Normal University

摘　　要：In this work we study the symmetry-energy coefficient of neutron-rich nuclei,and the temperature dependence of nuclear symmetry energy at low temperatures.An isobaric method is used to extract the symmetry-energy coefficients of neutron-rich nucleus(asym) at zero temperature(T) and asym/T at nonzero temperature in the measured 1A GeV124,136Xe+Pb reactions.T of fragment is obtained from the ratio of its asym to asym/T.The results show that,for fragment with the same neutron-excess(I=N Z),the heavier the fragment is,the higher T it has,and T tends to saturate around 1 MeV for the large mass fragments.It is also shown that the more neutron-rich the isobar is,the higher temperature it has.The T2dependence of symmetry energy of finite nucleus at low temperatures is verified by the extracted results.In this work we study the symmetry-energy coefficient of neutron-rich nuclei, and the temperature dependence of nuclear symmetry energy at low temperatures. An isobaric method is used to extract the symmetry-energy coefficients of neutron-rich nucleus （asm） at zero temperature （T） and asym/T at nonzero temperature in the measured 1A GeV 124＇136Xe＋Pb reactions. T of fragment is obtained from the ratio of its asym to asym/T. The results show that, for fragment with the same neutron-excess （I=N-Z）, the heavier the fragment is, the higher T it has, and T tends to saturate around 1 MeV for the large mass fragments. It is also shown that the more neutron-rich the isobar is, the higher temperature it has. The T2 dependence of symmetry energy of finite nucleus at low temperatures is verified by the extracted results.

关 键 词：丰中子核 对称能 反应 温度依赖性 铅 能量系数 非对称 等压法 

分 类 号：O571.5[理学—粒子物理与原子核物理]