Probing Sizes and Shapes of Nobelium Isotopes by Laser Spectroscopy

Area of Science:

• Nuclear Physics
• Atomic Physics
• Quantum Chemistry

Background:

• Previously, ground-state nuclear moments of heavy nuclei were indirectly inferred using nuclear spectroscopy, necessitating model assumptions.
• Direct probing of these moments was limited, hindering comprehensive understanding of nuclear properties.
• Advancements in laser spectroscopy and atomic structure calculations offer new possibilities for direct measurement.

Purpose of the Study:

• To directly measure differential mean-square charge radii of Nobelium isotopes (252, 253, 254No).
• To investigate changes in nuclear size and shape in heavy actinide nuclei.
• To complementarily measure nuclear deformation and probe neutron wave functions via hyperfine splitting.

Main Methods:

• Utilized laser spectroscopy for direct probing of nuclear moments.
• Employed modern atomic structure calculations for data analysis.
• Evaluated hyperfine splitting of 253No for deformation and nuclear spin/magnetic moment insights.

Main Results:

• Achieved unique access to differential mean-square charge radii for 252, 253, 254No.
• Nuclear density functional calculations accurately described charge radii changes in heavy actinides.
• Observed evidence of a central depression in the deformed proton density distribution for 252, 254No.

Conclusions:

• Laser spectroscopy provides a comprehensive, nuclear-model-independent method for studying heavy nuclei.
• The study offers direct insights into nuclear size, shape, and deformation of Nobelium isotopes.
• Findings contribute to a deeper understanding of nuclear structure in the heavy actinide region.