Clustering and pasta phases in nuclear density functional theory

TL;DR

This paper explores nuclear density functional theory to analyze clustering in nuclei and pasta phases in neutron star crusts, introducing localization measures and advanced boundary conditions for improved characterization.

Contribution

It introduces nucleonic localization as a tool to identify clusters and applies twist-averaged boundary conditions to study pasta phases in finite-volume DFT calculations.

Findings

Localization measures reveal clustering in nuclei and fissioning systems.

Twist-averaged boundary conditions enable finite-volume analysis of pasta phases.

Method enhances understanding of nuclear structure and neutron star matter.

Abstract

Nuclear density functional theory (DFT) is the tool of choice in describing properties of complex nuclei and intricate phases of bulk nucleonic matter. It is a microscopic approach based on an energy density functional representing the nuclear interaction. An attractive feature of nuclear DFT is that it can be applied to both finite nuclei and pasta phases appearing in the inner crust of neutron stars. While nuclear pasta clusters in a neutron star can be easily characterized through their density distributions, the level of clustering of nucleons in a nucleus can often be difficult to assess. To this end, we use the concept of nucleonic localization. We demonstrate that the localization measure provides us with fingerprints of clusters in light and heavy nuclei, including fissioning systems. Furthermore we investigate the rod-like pasta phase using twist-averaged boundary conditions, which enable calculations in finite volumes accessible by state of the art DFT solvers.