Ground state hyperfine splitting in 6,7Li atoms and the nuclear structure

Phys Rev Lett. 2013 Dec 13;111(24):243001. doi: 10.1103/PhysRevLett.111.243001. Epub 2013 Dec 9.

Abstract

Relativistic and QED corrections are calculated for a hyperfine splitting of the 2S1/2 ground state in 6,7Li atoms with a numerically exact account for electronic correlations. The resulting theoretical predictions achieve such a precision level that, by comparison with experimental values, they enable determination of the nuclear properties. In particular, the obtained results show that the 7Li nucleus, having a charge radius smaller than 6Li, has about a 40% larger Zemach radius. Together with known differences in the electric quadrupole and magnetic dipole moments, this calls for a deeper understanding of the Li nuclear structure.