A new look at the $\beta$-decay of $^{11}$Li

Following the development of a more intense $^{11}$Li beam at ISAC/TRIUMF, the study of the $\gamma$ spectrum, following the $\beta$-decay of $^{11}$Li, was re-investigated with the 8pi spectrometer, an array of 20 Compton-suppressed HPGe detectors. The addition of an inner array of plastic scintillators allowed data-taking in $\beta$-$\gamma$ coincidences, which significantly improved the signal to background ratio. Since most of the decay strength is observed to proceed through $\beta$-delayed one-neutron emission, the $\gamma$-spectrum is dominated by the decay of bound excited states of $^{10}$Be. These transitions exhibit characteristic Doppler-broadened lineshapes, due to the recoiling effect induced by the neutron emission. Analysis of these lineshapes and results from the new experiment will be presented.