Abstract
We propose an importance-truncation scheme for the large-scale nuclear shell model that extends its range of applicability to larger valence spaces and midshell nuclei. It is based on a perturbative measure for the importance of individual basis states that acts as an additional truncation for the many-body model space in which the eigenvalue problem of the Hamiltonian is solved numerically. Through a posteriori extrapolations of all observables to vanishing importance threshold, the full shell-model results can be recovered. In addition to simple threshold extrapolations, we explore extrapolations based on the energy variance. We apply the importance-truncated shell model for the study of in the valence space and of and in the space. We demonstrate the efficiency and accuracy of the approach, which pave the way for future applications of valence-space interactions derived in ab initio approaches in larger valence spaces.
- Received 1 September 2015
DOI:https://doi.org/10.1103/PhysRevC.93.021301
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