Schiff moments of deformed nuclei

TL;DR

This paper introduces a new method to accurately calculate Schiff moments in deformed nuclei using experimental data, and applies it to $^{153}$Eu, revealing a significantly enhanced Schiff moment due to low energy octupole modes.

Contribution

The paper develops a novel calculation method for Schiff moments based on experimental data, and provides the first such calculation for $^{153}$Eu, highlighting the impact of octupole modes.

Findings

Schiff moment in $^{153}$Eu is about 30 times larger than in spherical nuclei.

The enhancement is linked to low energy octupole modes.

The calculated Schiff moment is 30 times smaller than static octupole deformation estimates.

Abstract

Stimulated by recent suggestion of Cosmic Axion Spin Precession Experiment with Eu contained compound we develop a new method for accurate calculation of Schiff moments of even-odd deformed nuclei. The method is essentially based on experimental data on magnetic moments and E1,E3-amplitudes in the given even-odd nucleus and in adjacent even-even nuclei. Unfortunately such sets of data are not known yet for most of interesting nuclei. Fortunately the full set of data is available for $^{153}$Eu. Hence, we perform the calculation for $^{153}$Eu and find value of the Schiff moment. The value is about 30 times larger than a typical Schiff moment of a spherical heavy nucleus. The enhancement of the Schiff moment in $^{153}$Eu is related to the low energy octupole mode. On the other hand the value of Schiff moment we find is 30 times smaller than that obtained in the assumption of static octupole deformation.