Nuclear skin and the curvature of the symmetry energy

International audienceThe effect of correlations between the slope and the curvature of the symmetry energy on ground-state nuclear observables is studied within the extended Thomas-Fermi approximation. We consider different isovector probes of the symmetry energy, with a special focus on the neutron skin thickness of Pb208. We use a recently proposed metamodeling technique to generate a large number of equation of state models, where the empirical parameters are independently varied. The results are compared to a set of calculations using 17 different Skyrme interactions. We show that the curvature parameter plays a non-negligible role on the neutron skin, while the effect is reduced in Skyrme functionals because of the correlation with the slope parameter