5th International Symposium on Nuclear Symmetry Energy NuSYM15, June 29 - July 2, 2015 Kraków, POLAND

Xavier Viñas
University of Barcelona, SPAIN

### Dipole polarizability, neutron skin and symmetry energy

Abstract
In this talk I review our findings in recent years about the density dependence of the nuclear symmetry energy, characterized by its slope $L$, obtained through information provided by the neutron radius and the neutron skin thickness in finite nuclei. These quantities are extracted from the analysis of data obtained in measurements performed in aniprotonic atoms (1), from the parity-violating asymmetry in low-momentum transfer in polarized electron scattering in $^{208}$Pb (1) and from the electric dipole polarizability obtained via polarized proton inelastic scattering at forward angles in $^{208}$Pb (2) and $^{68}$Ni. All these experiments provide different constraints on the slope of the symmetry energy $L$, but the corresponding values have a considerable overlap in the range around 50 MeV $\le L \le$ 70 MeV, in a reasonable agreement with other estimates that use different observables and methods to extact $L$.

[1] X. Viñas, M. Centelles, X. Roca-Maza and M. Warda, Eur. Phys. J. 50 27 (2014) and references therein.
[2] X. Roca-Maza et al, Phys. Rev. C88, 024316 (2013).