Electric dipole polarizability of ${}^{58}$Ni

Abstract

The electric dipole strength distribution in ${}^{58}$Ni between 6 and 20 MeV has been determined from proton inelastic scattering experiments at very forward angles at RCNP, Osaka. The experimental data are rather well reproduced by quasiparticle random-phase approximation calculations including vibration coupling, despite a mild dependence on the adopted Skyrme interaction. They allow an estimate of the experimentally inaccessible high-energy contribution above 20 MeV, leading to an electric dipole polarizability ${\alpha }_{\mathrm{D}}{(}^{58}\mathrm{Ni})=3.48(31)$ fm${}^3$. This serves as a test case for recent extensions of coupled-cluster calculations with chiral effective field theory interactions to nuclei with two nucleons on top of a closed-shell system.

Comments: 8 pages, 4 figures