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We report on measurements of the hyperfine $A, B$ and $C$-constants of the $3d4s^2 ~^2D_{5/2}$ and $3d4s^2 ~^2D_{3/2}$ 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.

We present a comprehensive mean-field calculation of the Schiff moment of the nucleus 225Ra, the quantity which determines the static electric dipole moment of the corresponding atom if time-reversal (T) invariance is violated in the nucleus. The calculation breaks all possible intrinsic symmetries of the nuclear mean field and includes, in particular, both exchange and direct terms from the full finite-range T-violating nucleon-nucleon interaction, and the effects of short-range correlations. The resulting Schiff moment, which depends on three unknown T-violating pion-nucleon coupling constants, is much larger than in 199Hg, the isotope with the best current experimental limit on its atomic electric-dipole moment., 4 pages, 2 figures; this version (references added) to be published in PRL

Rotational bands have been found in 57Co using the 28Si(32S,3p) reaction at 130 MeV. The bands, extending the mass 60 region of large deformation down to Z=27, are signature-partner sequences. Their quadrupole moments are similar to those of bands in the neighboring nuclei. The features of the new bands are described by Skyrme Hartree-Fock calculations favoring a configuration assignment with one neutron and one proton excited in the respective 1g9/2 intruder orbital. An attempt to describe the magnetic (M1) properties of the signature-partner structure is also presented.

Recent high-spin studies in the mass 60 region of highly deformed and superdeformed shapes are discussed. The experimental data are from reaction channel selected γ-spectroscopic measurements at Gammasphere. Points of special attention are rotational bands in nuclei below the Z=28 shell gap and measurements of transition quadrupole moments throughout the region.

Using on-line separation combined with γ-ray and conversion-electron spectroscopy, decay properties of neutron-deficient isotopes were measured near 100Sn. The QEC values, the excitation energies of 1+ levels, and the strength for 0+→1+ Gamow-Teller β transitions, as obtained for the decay of the even-even nuclides 94Ru, 96–100Pd, 100–104Cd, and 104–110Sn, are compared with predictions from shell-model calculations including deformation, pairing and core-polarization effects. The quenching of the Gamow-Teller strength, as deduced from this comparison, is presented. Furthermore, low-lying levels in 104In are discussed with particular emphasis on a possibility of observing spin-mixing.