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 a^(*)_(sym)/A≡4asym/A of nuclei.A(sub)magic neutro...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 a^(*)_(sym)/A≡4asym/A of nuclei.A(sub)magic neutron magic number N=40 is suggested in a very neutron-rich nucleus,and a^(*)_(sym)/A of a nucleus is found to decrease when its mass increases.The a^(*)_(sym)/A of a very neutron-rich nucleus with large mass saturates.The volume-symmetry coefficients(b_(v))and surface-symmetry coefficients(b_(s))of a neutron-rich nucleus are extracted from a sym*/A by a correlation a^(*)_(sym)/A=bv/A-b s/A^(4/3).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.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 10905017the Program for Innovative Research Team in Science and Technology under Grant No 2010IRTSTHN002the Universities of Henan Province,and the Young Teacher Project in Henan Normal University.
文摘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 a^(*)_(sym)/A≡4asym/A of nuclei.A(sub)magic neutron magic number N=40 is suggested in a very neutron-rich nucleus,and a^(*)_(sym)/A of a nucleus is found to decrease when its mass increases.The a^(*)_(sym)/A of a very neutron-rich nucleus with large mass saturates.The volume-symmetry coefficients(b_(v))and surface-symmetry coefficients(b_(s))of a neutron-rich nucleus are extracted from a sym*/A by a correlation a^(*)_(sym)/A=bv/A-b s/A^(4/3).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.
