Continuum Random Phase Approximation for Relativistic Point Coupling Models

TL;DR

This paper develops a relativistic continuum RPA method based on density functional theory to analyze collective excitations in spherical nuclei, including resonance energies and strength distributions, with comparisons to experimental data.

Contribution

It introduces a relativistic continuum RPA framework derived from covariant density functionals for studying nuclear excitations.

Findings

Accurately predicts resonance centroid energies.

Provides detailed strength distributions for various resonances.

Shows good agreement with experimental data.

Abstract

Relativistic Continuum Random Phase Approximation (CRPA) is used to investigate collective excitation phenomena in several spherical nuclei along the periodic table. We start from relativistic mean field calculations based on a covariant density functional with density dependent zero range forces. From the same functional an effective interaction is obtained as the second derivative with respect to the density. This interaction is used in relativistic continuum-RPA calculations for the investigation of isoscalar monopole, isovector dipole and isoscalar quadrupole resonances of spherical nuclei. In particular we study the low-lying E1 strength in the vicinity of the neutron evaporation threshold. The properties of the resonances, such as centroid energies and strengths distributions are compared with results of discrete RPA calculations for the same model as well as with experimental data.