Abstract
The root-mean-square (rms) nuclear charge radius of , the most neutron-rich of all particle-stable nuclei, has been determined for the first time to be 1.93(3) fm. In addition, the rms charge radius of was measured to be 2.068(11) fm, in excellent agreement with a previous result. The significant reduction in charge radius from to is an indication of the change in the correlations of the excess neutrons and is consistent with the neutron halo structure. The experiment was based on laser spectroscopy of individual helium atoms cooled and confined in a magneto-optical trap. Charge radii were extracted from the measured isotope shifts with the help of precision atomic theory calculations.
- Received 21 November 2007
DOI:https://doi.org/10.1103/PhysRevLett.99.252501
©2007 American Physical Society