Symmetry-adapted no-core shell model

Article By:

Dytrych, Tomas Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana.

Launey, Kristina D. Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana.

Draayer, Jerry P. Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana.

Last reviewed:2014

DOI:https://doi.org/10.1036/1097-8542.YB140314

The symmetry-adapted no-core shell model (SA-NCSM) is a nuclear-structure many-body theory that capitalizes on dominant symmetries discovered in atomic nuclei. It is designed, by utilizing cutting-edge computer resources, to provide nuclear system simulations from first principles (ab initio), which means the interaction between the constituent protons and neutrons of a nucleus is realistic—typically tied to underlying quark-gluon considerations—and hence powers the model with a predictive capability. The SA-NCSM builds upon a novel symmetry-adapted concept that winnows the configurations available to protons and neutrons to only the physically most relevant ones, thereby conquering a previously unknown realm. On the one hand, particles can occupy configurations not accessible heretofore but key to important correlations, and on the other hand, new regions of heavier nuclear species are opened, for the first time, to ab initio investigations. These include some rare isotopes, which are inaccessible by current experiments and ab initio methods but are key in cosmic processes that are mainly nuclear-reaction driven, such as stellar evolution and explosions (including novae, supernovae, and x-ray bursts) as well as the formation of elements (nucleosynthesis).

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