Surface and Volume Symmetry Energy Coefficients of a Neutron-Rich Nucleus
MA Chun-Wang1**, YANG Ju-Bao1, YU Mian2, PU Jie1,3, WANG Shan-Shan1, WEI Hui-Ling1
1Department of Physics, Henan Normal University, Xinxiang 453007 2Department of Life Sciences and Technology, Xinxiang Medical University, Xinxiang 453003 3Department of Nuclear Physics, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800
Abstract：Using an isobaric method, the symmetry-energy coefficient (asym) of a neutron-rich nucleus is obtained from experimental binding energies. The shell effects are shown in asym*/A≡4asym/A of nuclei. A (sub)magic neutron magic number N=40 is suggested in a very neutron-rich nucleus, and asym*/A of a nucleus is found to decrease when its mass increases. The asym*/A of a very neutron-rich nucleus with large mass saturates. The volume-symmetry coefficients (bv) and surface-symmetry coefficients (bs) of a neutron-rich nucleus are extracted from a sym*/A by a correlation asym*/A=bv/A?b s/A4/3. It is found that bv and bs decrease when the nucleus becomes more neutron-rich, and tend to saturate in the very neutron-rich nucleus. A linear correlation between b v and bs is obtained in nuclei with different neutron-excess I, and bv of I>7 nuclei is found to coincide with the results of infinite nuclear matter a sym=32 ±4 MeV, and bs/bv of the nucleus is found to coincide with the results of the finite-range liquid-drop model results.
. [J]. 中国物理快报, 2012, 29(9): 92101-092101.
MA Chun-Wang, YANG Ju-Bao, YU Mian, PU Jie, WANG Shan-Shan, WEI Hui-Ling. Surface and Volume Symmetry Energy Coefficients of a Neutron-Rich Nucleus. Chin. Phys. Lett., 2012, 29(9): 92101-092101.
2012, Vol. 29 
