Global study of beyond-mean-field correlation energies in covariant energy density functional theory using a collective Hamiltonian method

TL;DR

This study performs a comprehensive analysis of dynamic correlation energies in covariant energy density functional theory across 575 nuclei, significantly improving mass predictions by incorporating beyond-mean-field effects through a collective Hamiltonian approach.

Contribution

It is the first global study using a five-dimensional collective Hamiltonian to include beyond-mean-field correlation energies in covariant energy density functional calculations.

Findings

RMS deviation of nuclear masses reduced to 1.14 MeV

Improved accuracy over other CEDFs like NL3* and DD-ME2

Separation energy deviations decreased by approximately 34%

Abstract

We report the first global study of dynamic correlation energies (DCEs) associated with rotational motion and quadrupole shape vibrational motion in a covariant energy density functional (CEDF) for 575 even-even nuclei with proton numbers ranging from $Z=8$ to $Z=108$ by solving a five-dimensional collective Hamiltonian, the collective parameters of which are determined from triaxial relativistic mean-field plus BCS calculation using the PC-PK1 force. After taking into account these beyond mean-field DCEs, the root-mean-square (rms) deviation with respect to nuclear masses is reduced significantly down to 1.14 MeV, which is smaller than those of other successful CEDFs: NL3* (2.96 MeV), DD-ME2 (2.39 MeV), DD-ME$\delta$ (2.29 MeV) and DD-PC1 (2.01 MeV). Moreover, the rms deviation for two-nucleon separation energies is reduced by $\sim34\%$ in comparison with cranking prescription.