Abstracts Category : Other

Covariant density functional theory: Global performance and rotating nuclei

by Debisree Ray

Covariant density functional theory (CDFT) is a modern theoretical tool for the descriptionof nuclear structure physics. Here different physical properties of the groundand excited states in atomic nuclei have been investigated within the CDFT frameworkemploying three major classes of the state-of-the-art covariant energy density functionals. The global performance of CEDFs for even-even nuclei are investigated and the <i>systematictheoretical uncertainties</i> are estimated within the set of four CEDFs in known regionsof the nuclear chart and their propagation towards the neutron drip line. Large-scale axialrelativistic Hartree-Bogoliubov (RHB) calculations are performed for even-even nuclei tocalculate different ground state observabvles. The predictions for the two-neutron drip lineare also compared in a systematic way with the non-relativistic results. CDFT has been applied for systematic study of extremely deformed, rotating <i>N Z</i>nuclei of the <i>A</i> 40 mass region. At spin zero such structures are located at high energieswhich prevents their experimental observation. The rotation acts as a tool to bring theseexotic shapes down to the yrast line so that their observation could become possible witha future generation detectors such as GRETA or AGATA. The major physical observablesof such structures, the underlying single-particle structure and the spins at which theybecome yrast or near yrast are defined. The search for the fingerprints of clusterization andmolecular structures is performed and the configurations with such features are discussed. CDFT has been applied to study fission barriers of superheavy nuclei and related systematictheoretical uncertainties in the predictions of inner fission barrier heights in superheavyelements. Systematic uncertainties are substantial in superheavy elements and theirbehavior as a function of proton and neutron numbers contains a large random component.The benchmarking of the functionals to the experimental data on fission barriers in theactinides allows reduction of the systematic theoretical uncertainties for the inner fissionbarriers of unknown superheavy elements. However, even then they on average increasewhen moving away from the region where benchmarking has been performed. Advisors/Committee Members: Gautam Rupak Lan Tai Moong (committee member), Jeffry A. Winger (committee member), Dipangkar Dutta (committee member), Yaroslav Koshka (committee member), Anatoli Afanasjev (committee member).