Nuclear moments of nuclei in the neighborhood of the neutron drip line.

Based on the β-NMR method with spin-polarized radioactive-isotope beams, we have been conducting a series of experiments at RIKEN for the measurement the magnetic moments and electric quadrupole moments of light unstable nuclei. From the systematic measurements of nuclear moments in the unstable nuclear region, the effects of the neutron excess on the structure have been discussed. In the μ-moment measurements of the nitrogen isotopes, the outward-directed deviation of μ(17N) and μ(19N) from the Schmidt value were observed. In the case of Q-moment, our experimental data show large discrepancy from the shell-model predictions if neutron and proton effective charges are assumed to be constant. By introducing an isospin dependence to the effective charges, the observed Q-moments of boron isotopes can be explained. We also applied the result of μ-moment measurements to the Iπ assignment. Owing to the large difference of μ values among expected Iπ candidates, Iπ(17C)=3/2+ has been definitely assigned. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]