New measurement and reevaluation of the nuclear magnetic and quadrupole moments of $^{8}$Li and $^{9}$Li

The nuclear magnetic moment of $^{9}$Li and the quadrupole moments of $^{8}$Li and $^{9}$Li have been measured using $\beta$-asymmetry detection of nuclear magnetic resonance ($\beta$-NMR) on optically polarized beams at ISOLDE/CERN. The radioactive beams were implanted in Si for g factor measurements and in Zn, LiNbO$_{3}$, and LiTaO$_{3}$ crystals for quadrupole moment measurements. The electric field gradient V$_{zz}$ = 4.26(4) $\times$10$^{15}$ V/cm$^{2}$ is deduced for Li in Zn. Using a recently adopted reference value Q($^{7}$Li) = -40.0(3) mb, we reevaluated all earlier reported nuclear quadrupole moments of $^{8}$Li and $^{9}$Li. Based on all available previous and present data, the adopted quadrupole moments for these isotopes are Q($^{8}$Li) = +31.4(2) mb and Q($^{9}$Li) = - 30.6(2) mb. The magnetic moment of $^{9}$Li is deduced as $\mu(^{9}$Li) = 3.43678(6)$\mu\scriptstyle_\textrm{N}$ . The values are compared to predictions from shell-model and cluster-model calculations.