Complete Electric Dipole Response in 120Sn and 208Pb and Implications for Neutron Skin and Symmetry Energy
Complete Electric Dipole Response in 120Sn and 208Pb and Implications for Neutron Skin and Symmetry Energy
复制标题
DOI：
10.1051/epjconf/20159301029
复制
发表时间：
2015-05
期刊：
影响因子：
--
通讯作者：
P. Neumann-Cosel
中科院分区：
文献类型：
--
作者：
P. Neumann-Cosel
能量为几百 MeV 且包括 0° 的极端前向角的偏振质子散射已被确立为一种新工具，可提取高达约 20 MeV 激发能量的原子核中的完整 E1 响应。 208 Pb 的案例研究表明与其他电磁探头具有极好的一致性。从 B(E1) 强度信息可以推导出电偶极子极化率，它与中子表皮和对称能参数密切相关。最近，我们以相当的精度提取了 120 Sn 的极化率。这两个结果的结合进一步限制了对称能量参数，并对平均场模型提出了挑战，因为相对论和许多 Skyrme 参数化无法同时重现这两个实验结果。
Polarized proton scattering at energies of a few 100 MeV and extreme forward angles including 0° has been established as a new tool to extract the complete E1 response in nuclei up to excitation energies of about 20 MeV. A case study of 208 Pb demonstrates excellent agreement with other electromagnetic probes. From the information on the B(E1) strength one can derive the electric dipole dipole polarizability, which is strongly correlated to the neutron skin and to parameters of the symmetry energy. Recently, we have extracted the polarizability of 120 Sn with a comparable precision. The combination of both results further constrains the symmetry energy parameters and presents a challenge for mean-field models, since the relativistic and many Skyrme parameterizations cannot reproduce both experimental results simultaneously.