Nuclear properties of the exotic high-spin isomerHfm2178from collinear laser spectroscopy

The complete hyperfine spectrum in the optical transition 5${\mathit{d}}^2$6${\mathit{s}}^2$ ${}_{}{}^3{}_{}{}^{}$ ${\mathit{P}}_2$→5d6${\mathit{s}}^2$6p ${}_{}{}^1{}_{}{}^{}$ ${\mathit{P}}_1$ of ${}_{}{}^{178}{}_{}{}^{}\mathrm{Hf}_{}^{\mathrm{m}2\mathrm{}}{}_{}{}^{}$ was recorded by collinear laser spectroscopy using nanogram amounts of samples. The quadrupole moment and isomer shift were determined for the first time as well as a precise value and the sign of the magnetic dipole moment. The change in nuclear mean-square charge radius between the isomeric state ${}_{}{}^{178}{}_{}{}^{}\mathrm{Hf}_{}^{\mathrm{m}2\mathrm{}}{}_{}{}^{}$ and the ground state ${}_{}{}^{178}{}_{}{}^{}\mathrm{Hf}_{}^{\mathit{g}}{}_{}{}^{}$ was evaluated as δ〈${\mathit{r}}^2$ ${\mathrm{〉}}^{178.178\mathrm{m}2}$=-0.059(9) ${\mathrm{fm}}^2$. From the hyperfine A and B factors the magnetic moment ${\mathrm{\mu }}_{\mathit{I}}^{178\mathrm{m}2}$=+8.16(4) nuclear magnetons and the spectroscopic quadrupole moment ${\mathit{Q}}_{\mathit{s}}^{178\mathrm{m}2}$=+6.00(7) b were were extracted.