Preliminary β-NQR spectra for 8,9,11Li. Red filled circles denote positive polarity spectra; open squares denote negative polarity. The solid and dotted lines in the 11Li spectrum are the Gaussian fits used to extract the central frequency.
The measurements for 8Li (which is used as the reference isotope) and 9Li have already been completed, yielding a ratio between their quadrupole moments of 0.96676(9) which is in line with, but a marked improvement upon, the previous literature value of 0.975(9). A preliminary run has also been performed for 11Li, but as can be seen from its spectrum much more data is needed for a satisfying result. This preliminary data puts the ratio Q11/Q9 at a value of 1.077(1), which also agrees with previous literature but already reduces its error by an order of magnitude. More data will enable the determination of systematic error sources and also add to this measurement's statistical power, improving both its accuracy and its precision.
 Borremans et al., 2005, Phys. Rev. C, 044309