Study of the $\beta$-decay of $^{11}$Li at ISAC/TRIUMF

The $\beta$-decay of $^{11}$Li was investigated using the 8$\pi$ $\beta$-decay spectrometer, an array of 20 Compton-suppressed HPGe detectors and 20 plastic scintillators for $\beta$-particle detection. Doppler-broadened line shapes appear in the experimental spectrum, resulting from the decay of excited states of $^{10}$Be populated by $\beta$-delayed neutron emission. Using a Monte Carlo simulation, we have simulated the $\beta$-delayed neutron decay and subsequent $\gamma$-ray emission, in order to explore the excited states in $^{10}$Be and the neutron-emitting states in $^{11}$Be. Overall agreement is observed with the two most recent studies [F. Sarazin et al, PRC70 (2004) and Y.Hirayama et al, PLB611 (2005)]. Analysis however also suggests the existence of small contributions from previously unobserved neutron branches.