Atomic calculations of the hyperfine-structure anomaly in gold

The magnetic hyperfine-structure constants have been calculated for low-lying levels in a neutral gold atom and a goldlike ion of mercury taking into account the Bohr-Weisskopf (BW) effect. The BW effect is represented as a product of atomic and nuclear (d(nuc)) factors. We have calculated the atomic factors, which enable one to extract BW-correction values for far from stability gold nuclei from the experimental data. The possible uncertainty of our atomic calculations have been estimated by the comparison with the available experimental data. It has been shown that the standard single-particle approach in d(nuc) calculation reasonably well describes experimental data for 11/2(-) gold isomers and the 3/2(+) ground state of Au-199. At the same time, it fails to describe the hyperfine constant in Au-197. This indicates the more pronounced configuration mixing in Au-197 than in Au-199.

Automated summary

The study calculated the magnetic hyperfine-structure constants for low-lying levels in a neutral gold atom and a goldlike ion of mercury, considering the Bohr-Weisskopf effect. By calculating the atomic factors, it was possible to extract BW-correction values for gold nuclei far from stability from experimental data. The results showed that the standard single-particle approach performed reasonably well for some levels in Au-199, but failed to describe the hyperfine constant in Au-197 due to more pronounced configuration mixing.