Effect of Wigner energy on the symmetry energy coefficient in nuclei
The nuclear symmetry energy coefficient（including the coefficient asym^（4） of the I^4 term） of finite nuclei is extracted by using the differences of available experimental binding energies of isobaric nuclei.It is found that the extracted symmetry energy coefficient asym^＊（A,I） decreases with incre...
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| Published in | Chinese physics C Vol. 40; no. 9; pp. 41 - 46 |
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| Main Author | |
| Format | Journal Article |
| Language | English |
| Published |
01.09.2016
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| Subjects | |
| Online Access | Get full text |
| ISSN | 1674-1137 0254-3052 |
| DOI | 10.1088/1674-1137/40/9/094101 |
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| Summary: | The nuclear symmetry energy coefficient（including the coefficient asym^（4） of the I^4 term） of finite nuclei is extracted by using the differences of available experimental binding energies of isobaric nuclei.It is found that the extracted symmetry energy coefficient asym^＊（A,I） decreases with increasing isospin asymmetry I,which is mainly caused by Wigner correction,since esym^＊ is the summation of the traditional symmetry energy esym and the Wigner energy ew.We obtain the optimal values J = 30.25±0.10 MeV,ass=56.18±1.25 MeV,asym^（4） = 8.33±1.21 MeV and the Wigner parameter x= 2.38 ±0.12 through a polynomial fit to 2240 measured binding energies for nuclei with20 ≤ A ≤ 261 with an rms deviation of 23.42 keV.We also find that the volume symmetry coefficient J≌ 30 MeV is insensitive to the value x,whereas the surface symmetry coefficient ass and the coefficient asym^（4） are very sensitive to the value of x in the range 1≤x≤4.The contribution of the asym^（4） term increases rapidly with increasing isospin asymmetry I.For very neutron-rich nuclei,the contribution of the asym^（4） term will play an important role. |
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| Bibliography: | 11-5641/O4 symmetry energy, Wigner energy, binding energy, isobaric nuclei The nuclear symmetry energy coefficient（including the coefficient asym^（4） of the I^4 term） of finite nuclei is extracted by using the differences of available experimental binding energies of isobaric nuclei.It is found that the extracted symmetry energy coefficient asym^＊（A,I） decreases with increasing isospin asymmetry I,which is mainly caused by Wigner correction,since esym^＊ is the summation of the traditional symmetry energy esym and the Wigner energy ew.We obtain the optimal values J = 30.25±0.10 MeV,ass=56.18±1.25 MeV,asym^（4） = 8.33±1.21 MeV and the Wigner parameter x= 2.38 ±0.12 through a polynomial fit to 2240 measured binding energies for nuclei with20 ≤ A ≤ 261 with an rms deviation of 23.42 keV.We also find that the volume symmetry coefficient J≌ 30 MeV is insensitive to the value x,whereas the surface symmetry coefficient ass and the coefficient asym^（4） are very sensitive to the value of x in the range 1≤x≤4.The contribution of the asym^（4） term increases rapidly with increasing isospin asymmetry I.For very neutron-rich nuclei,the contribution of the asym^（4） term will play an important role. Jun-Long Tian, Hai-Tao Cui,Teng Gao, Ning Wang （1 School of Physics and Electrical Engineering, Anyang Normal University, Anyang 455000, China; 2 Department of Physics, Guangxi Normal University, Guilin 541004, China; 3 State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China） |
| ISSN: | 1674-1137 0254-3052 |
| DOI: | 10.1088/1674-1137/40/9/094101 |