The Giant Dipole Resonance as a quantitative constraint on the symmetry energy

TL;DR

This paper demonstrates that the centroid of the Giant Dipole Resonance in spherical nuclei can serve as a precise experimental constraint on the symmetry energy at sub-saturation densities, refining theoretical nuclear models.

Contribution

It establishes a strong correlation between GDR centroid energies and the symmetry energy in Skyrme functionals, providing a new method to constrain nuclear effective interactions.

Findings

GDR centroid in 208Pb correlates with symmetry energy at rho=0.1 fm^{-3}

Experimental GDR data constrains symmetry energy to 23.3-24.9 MeV

Supports using GDR as a quantitative constraint in nuclear models

Abstract

The possible constraints on the poorly determined symmetry part of the effective nuclear Hamiltonians or effective energy functionals, i.e., the so-called symmetry energy S(rho), are very much under debate. In the present work, we show that the value of the symmetry energy associated with Skyrme functionals, at densities rho around 0.1 fm^{-3}, is strongly correlated with the value of the centroid of the Giant Dipole Resonance (GDR) in spherical nuclei. Consequently, the experimental value of the GDR in, e.g., 208Pb can be used as a constraint on the symmetry energy, leading to 23.3 MeV < S(rho=0.1 fm^{-3}) < 24.9 MeV.