A nucleus-dependent valence-space approach to nuclear structure

Understand

We present a nucleus-dependent valence-space approach for calculating ground and excited states of nuclei, which generalizes the shell-model in-medium similarity renormalization group to an ensemble reference with fractionally filled orbitals.

• Because the ensemble is used only as a reference, and not to represent physical states, no symmetry restoration is required.
• This allows us to capture 3N forces among valence nucleons with a valence-space Hamiltonian specifically targeted to each nucleus of interest.
• Predicted ground-state energies from carbon through nickel agree with results of other large-space ab initio methods, generally to the 1\% level.