Complete electric dipole response in 120Sn and 208Pb and implications for neutron skin and symmetry energy

NUBA Conference Series -1: Nuclear Physics and Astrophysics

物理学;天文学

Von Neumann-Cosel, Peter^1

Institut für Kernphysik, Technische Universität Darmstadt, Darmstadt

64289, Germany^1

关键词: Electric dipole;    Electromagnetic probes;    Mean field models;    Polarizabilities;    Polarized protons;    Strength distribution;    Symmetry energies;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/590/1/012017/pdf
DOI  :  10.1088/1742-6596/590/1/012017

学科分类：天文学(综合)

来源: IOP

【 摘 要 】

Polarized proton scattering at energies of a few 100 MeV and very forward angles including 0° has been established as a new tool to extract the complete E1 strength distribution in nuclei for excitation energies between about 5 and 20 MeV. A case study of208Pb 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 of120Sn with a comparable precision. The combination of both results further constrains the symmetry energy parameters and presents a challenge for mean-field models, since relativistic and many Skyrme parameterizations cannot reproduce both experimental results simultaneously.