Effects of beyond-mean-field correlations on nuclear Schiff moments

TL;DR

This study calculates nuclear Schiff moments in certain diamagnetic atoms using advanced multireference covariant density functional theory, revealing how beyond-mean-field correlations influence these moments and their relation to electric dipole transitions.

Contribution

It introduces the incorporation of beyond-mean-field correlations via the generator coordinate method with projection into Schiff moment calculations, a novel approach in this context.

Findings

Beyond-mean-field effects can enhance or suppress Schiff moments.

In $^{225}$Ra, these effects reduce the enhancement from octupole deformation.

A correlation exists between intermediate state contributions and electric dipole transition strengths.

Abstract

We compute the nuclear Schiff moments of the diamagnetic atoms $^{129}$Xe, $^{199}$Hg, and $^{225}$Ra in multireference covariant density functional theory. Beyond-mean-field correlations, arising from symmetry restoration and shape mixing, are incorporated via the generator coordinate method with projection onto states with well-defined parity, particle number, and angular momentum. Our results reveal a correlation between the contributions of nuclear intermediate states to Schiff moments and the electric dipole transition strengths from these states to the ground state. The new beyond-mean-field effects can either enhance or suppress the Schiff moments. In $^{225}$Ra, they do the latter, reducing the enhancement from octupole deformation somewhat.