JPhysG

[paper] The first self-consistent calculation of quadrupole moments of odd semi-magic nuclei accounting for phonon-induced corrections

The first self-consistent calculation of quadrupole moments of odd semi-magic nuclei accounting for phonon-induced corrections

E.E. Saperstein et al.

doi: 10.1088/1361-6471/aa65f5

The self-consistent model, developed previously to describe phonon coupling (PC) effects in magnetic moments of odd magic and semi-magic nuclei, is extended to quadrupole moments. It is based on the theory of finite Fermi systems with the use of the perturbation theory in g_L², where g_L is the vertex creating the L-phonon. Accounting for the phonon tadpole diagrams is an important ingredient of this model. The calculation scheme is based on the Fayans energy density functional DF3-a and does not contain any adjusted parameters. The odd In and Sb isotopes are considered, which are the proton-odd neighbors of even tin nuclei. The 2₁⁺ phonon is taken into account in which the quadrupole moment is one ingredient of the calculation scheme. The corresponding values were found by us previously. Two main PC corrections, due to the phonon Z-factor and due to the phonon-induced interaction, have opposite signs and strongly cancel each other, leaving room for other ‘small’ corrections, so that the resulting PC correction is much lower than the absolute values of each of the two main ones. However, it remains noticeable, making the overall agreement with the data significantly better.

Apr 24, 2017 by Theo quadrupole theory 0

[paper] The on-line low temperature nuclear orientation facility NICOLE

The on-line low temperature nuclear orientation facility NICOLE

T. Ohtsubo et al.

doi: 10.1088/1361-6471/aa5f22

We review major experiments and results obtained by the on-line low temperature nuclear orientation method at the NICOLE facility at ISOLDE, CERN since the year 2000 and highlight their general physical impact. This versatile facility, providing a large degree of controlled nuclear polarization, was used for a long-standing study of magnetic moments at shell closures in the region Z = 28, N = 28–50 but also for dedicated studies in the deformed region around A ~ 180. Another physics program was conducted to test symmetry in the weak sector and constrain weak coupling beyond V–A. Those two programs were supported by careful measurements of the involved solid state physics parameters to attain the full sensitivity of the technique and provide interesting interdisciplinary results. Future plans for this facility include the challenging idea of measuring the beta–gamma–neutron angular distributions from polarized beta delayed neutron emitters, further test of fundamental symmetries and obtaining nuclear structure data used in medical applications. The facility will also continue to contribute to both the nuclear structure and fundamental symmetry test programs.

Mar 16, 2017 by Theo experiment 0

[paper] Nuclear charge radii and electromagnetic moments of radioactive scandium isotopes and isomers

Nuclear charge radii and electromagnetic moments of radioactive scandium isotopes and isomers

M. Avgoulea et al.

doi: 10.1088/0954-3899/38/2/025104

Collinear laser spectroscopy experiments with the Sc⁺ transition 3d4s ³D₂ → 3d4p ³F3 at λ = 363.1 nm were performed on the ^42–46Sc isotopic chain using an ion guide isotope separator with a cooler-buncher. Nuclear magnetic dipole and electric quadrupole moments as well as isotope shifts were determined from the hyperfine structure for five ground states and two isomers. Extensive multi-configurational Dirac–Fock calculations were performed in order to evaluate the specific mass-shift, MSMS, and field-shift, F, parameters which allowed evaluation of the charge radii trend of the Sc isotopic sequence. The charge radii obtained show systematics more like the Ti radii, which increase towards the neutron shell closure N = 20, than the symmetric parabolic curve for Ca. The changes in mean-square charge radii of the isomeric states relative to the ground states for ⁴⁴Sc and ⁴⁵Sc were also extracted. The charge radii difference between the ground and isomeric states of ⁴⁵Sc is in agreement with the deformation effect estimated from the B(E2) measurements but is smaller than the deformation extracted from the spectroscopic quadrupole moments.

Jan 5, 2011 by Theo experiment g factor 0

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