Microscopic origin of ground-state and gamma-band g-factor differences

Investigate the microscopic origin of the differences between the magnetic g-factors of the gamma band and the ground-state band in dysprosium isotopes, and determine their relation to the Hamiltonian used in the pseudo-SU(3) model.

Background

The paper examines the ratio r = g(2+_gamma)/g(2+_gsb) as a possible indicator of triaxiality in dysprosium isotopes. The pseudo-SU(3) calculations predict a nonmonotonic evolution of this ratio along the isotopic chain, with values approaching or exceeding unity near the midshell region.

The authors relate the behavior of the g-factors to the competing effects of the quadrupole-quadrupole interaction, which preserves and enhances SU(3) symmetry, and pairing, which breaks SU(3) symmetry. They state that a more detailed microscopic explanation of the differences between gamma-band and ground-state-band g-factors, and of how those differences depend on the employed Hamiltonian, remains to be developed.

References

A more detailed study of the microscopic origin of the differences in the values between $g(2+_\gamma)$ and $g(2+_{gsb})$ and its relation to the Hamiltonian employed is left for future work.

— Electromagnetic properties in $^{160-170}$Dy nuclei: A microscopic description by the pseudo-SU(3) shell model  (2609.28861 - Vargas et al., 24 Sep 2026) in Section G-factors and M1 transitions, paragraph following the discussion of the ratio r

However, at this moment we cannot offer physical arguments to explain this discrepancy with respect to the standard collective model approach.

— Microscopic study of low-lying energy levels and electromagnetic properties in even-even $^{168-178}$Yb nuclei  (2609.28763 - Vargas et al., 23 Sep 2026) in Section 5, g-factors and quadrupole moments