Changes in nuclear mean square charge radii of stable krypton isotopes

The isotope shifts of stable even Kr isotopes (A = 78 through A = 86) in the optical transitions at 432 nm and 557 nm were measured by means of polarization laser spectroscopy. The observed shifts are consistent with earlier results for other transitions. From the isotope shifts the changes in the nuclear mean square charge radii delta were inferred using preliminary muonic isotope shift data. Starting from 78Kr, a monotonic decrease of with increasing mass number is found throughout the g9/2 neutron shell. The effect on delta of nuclear deformations as well as possible contributions due to changes in the skin thickness of the nuclear charge distribution are discussed. (orig.)