Applications of Nuclear Structure Theory

Michigan State University, East Lansing MI

Investigators

Abstract

The properties of atomic nuclei are essential for our understanding of many areas of physics. At the most fundamental level, nuclei are composed of quarks held together by the exchange of gluons. The grouping of quarks into baryons and mesons provides the ingredients for our understanding of nuclei as being composed of protons and neutrons held together by the exchange of mesons. The stable isotopes provide about 250 different combinations of protons and neutrons. About 3,000 more combinations have been made in the laboratory, and many more, in particular those with a large excess of neutrons, will be made and studied at the next generation of facilities such as the Facility for Rare Isotope Beams (FRIB) at Michigan State University. Up to 7,000 different combinations of protons and neutrons were involved in the formation of the elements during the evolution of the universe. This project in nuclear structure theory will provide analytical models and computational tools for understanding the properties of these nuclei. The results of these studies will be applied to areas of fundamental physics and nuclear astrophysics where the nuclear properties are needed. This project will greatly expand the use of of Configuration Interaction (CI) and Energy Density Functional (EDF) models for nuclei. This will carried out on several levels. The PI will develop new Hamiltonians used for these methods with input from ab-initio models based on nucleon-nucleon scattering data together with empirical constraints from known experimental data. The PI will develop computational methods that allow for the solution of the quantum many-body problem that take into account the very large basis dimensions needed in the CI method. The PI will make applications of these results to many areas of physics interest. They will be used for collaborations with the experimental program at FRIB and other laboratories. They will be used to obtain nuclear matrix elements for studying fundamental physics with nuclei. They also will be used in collaboration with the Joint Institute for Nuclear Astrophysics and Center for the Evolution of the Elements (JINA-CEE) at MSU to calculate reaction rates needed for understanding supernovae and X-ray bursters, and for the nuclear equations of state needed for neutron stars and neutron star mergers. The graduate students supported by this project will have unique opportunities to train and contribute to high-profile research in nuclear theory. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.