Density Functional Theory studies of cluster states in nuclei

TL;DR

This paper uses nuclear energy density functional theory to investigate the formation and evolution of cluster states in various nuclei, revealing new insights into their structure and bonding mechanisms.

Contribution

It applies relativistic Hartree-Bogoliubov calculations with the DD-ME2 functional to predict cluster structures in both stable and neutron-rich nuclei, highlighting the role of deformation and degeneracy.

Findings

Cluster states predicted in excited configurations of multiple nuclei.

Neutron-rich Be and C nuclei exhibit molecular bonding of alpha particles.

Proton covalent bonding observed in $^{10}$C.

Abstract

The framework of nuclear energy density functionals is applied to a study of the formation and evolution of cluster states in nuclei. The relativistic functional DD-ME2 is used in triaxial and reflection-asymmetric relativistic Hartree-Bogoliubov calculations of relatively light $N = Z$ and neutron-rich nuclei. The role of deformation and degeneracy of single-nucleon states in the formation of clusters is analysed, and interesting cluster structures are predicted in excited configurations of Be, C, O, Ne, Mg, Si, S, Ar and Ca $N = Z$ nuclei. Cluster phenomena in neutron-rich nuclei are discussed, and it is shown that in neutron-rich Be and C nuclei cluster states occur as a result of molecular bonding of $\alpha$-particles by the excess neutrons, and also that proton covalent bonding can occur in $^{10}$C.