Impact Parameter Dependence of the Double Neutron/Proton Ratio of Nucleon Emissions in Isotopic Reaction Systems  

作　　者：张勋超 李宝安 陈列文 雍高产 

机构地区：[1]Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 [2]Graduate School of Chinese Academy of Sciences, Beijing 100049 [3]Department of Physics, Texas A&M University-Commerce, Commerce, Texas 75429-3011, USA [4]Institute of Theoretical Physics, Shanghai Jiao Tong University, Shanghai 200240 [5]Center of Theoreticai Nuclear Physics, Nationai Laboratory of Heavy Ion Accelerator, Lanzhou 730000

出　　处：《Chinese Physics Letters》2009年第5期60-63,共4页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant Nos 10710172, 10675082 and 10575071, the New Century Excellent Talent Project （NCET） of the Ministry of Education of China under Grant No NCET-05-0392, the Shanghai Rising-Star Program under Grant No 06QA14024, the SRF for ROCS, SEM of China, and the National Basic Research Program of China under Contract No 2007CB815004, the US National Science Foundation Awards PHY-0652548 and PHY-0757839, the Research Corporation under Award No 7123, and the Texas Coordinating Board of Higher Education Award No 003565-0004-2007.

摘　　要：Within the transport model IBUU04, we investigate the double neutron/proton ratio of free nucleons taken from two reaction systems using two Sn isotopes at a beam energy of 50 MeV/nucleon and with impact parameters 2fm, 4fm and 8fm, respectively. It is found that the double neutron/proton ratio from peripheral collisions is more sensitive to the density dependence of the symmetry energy than those from mid-central and central collisions.Within the transport model IBUU04, we investigate the double neutron/proton ratio of free nucleons taken from two reaction systems using two Sn isotopes at a beam energy of 50 MeV/nucleon and with impact parameters 2fm, 4fm and 8fm, respectively. It is found that the double neutron/proton ratio from peripheral collisions is more sensitive to the density dependence of the symmetry energy than those from mid-central and central collisions.

关 键 词：gamma-ray bursts GAMMA-RAYS RELATIVITY 

分 类 号：O572.2[理学—粒子物理与原子核物理] O572.24[理学—物理]