Precision measurement of the magnetic octupole moment in ${}^{45}$Sc as a test for state-of-the-art atomic- and nuclear-structure theory

Abstract

We report on measurements of the hyperfine $A,B$ and $C$-constants of the $3d4s^2{}^2{D}_{5/2}$ and $3d4s^2{}^2{D}_{3/2}$ atomic states in ${}^{45}$Sc. High-precision atomic calculations of the hyperfine fields of these states and second-order corrections are performed, and are used to extract $C_{5/2}=-0.06(6)$ kHz and $C_{3/2}=+0.04(3)$ kHz from the data. These results are one order of magnitude more precise than the available literature. From the combined analysis of both atomic states, we infer the nuclear magnetic octupole moment $\Omega =-0.07(53){\mu }_{N}b$, including experimental and atomic structure-related uncertainties. With a single valence proton outside of a magic calcium core, scandium is ideally suited to test a variety of nuclear models, and to investigate in-depth the many intriguing nuclear structure phenomena observed within the neighboring isotopes of calcium. We perform nuclear shell-model calculations of $\Omega$, and furthermore explore the use of Density Functional Theory for evaluating $\Omega$. From this, mutually consistent theoretical values of $\Omega$ are obtained, which are in agreement with the experimental value. This confirms atomic structure calculations possess the accuracy and precision required for magnetic octupole moment measurements, and shows that modern nuclear theory is capable of providing meaningful insight into this largely unexplored observable.

References in corpus (9)

• A new effective interaction for $0\hslash \omega$ shell model calculations in the sdpf valence space
• A new Skyrme interaction with improved spin-isospin properties
• Beyond the charge radius: the information content of the fourth radial moment
• Shell structure of potassium isotopes deduced from their magnetic moments
• Solution of universal nonrelativistic nuclear DFT equations in the Cartesian deformed harmonic-oscillator basis. (IX) HFODD (v3.06h): a new version of the program
• Ground-state properties of even and odd Magnesium isotopes in a symmetry-conserving approach
• Study of the magnetic octupole moment of ${}^{173}$Yb using collinear laser spectroscopy
• Properties of spherical and deformed nuclei using regularized pseudopotentials in nuclear DFT
• Appraising nuclear octupole moment contributions to the hyperfine structures in ${}^{211}$Fr

Cited by in corpus (5)

• Laser Spectroscopy for the Study of Exotic Nuclei
• Observation of the distribution of nuclear magnetization in a molecule
• Electromagnetic moments in the Sn-Gd region determined within nuclear DFT
• A new beamline for Resonant Excitation of Beams with Electromagnetic fields and Lasers (REBEL) and Stopping and Trapping of Radioactive Isotopes for Precision Experiments (STRIPE)
• Modelling of transient interference phenomena in collinear laser spectroscopy