Precision excited-state lifetime measurements of 7,8Li

Advancing computational capabilities are providing increasingly detailed insights into light nuclear systems through \textit{ab initio} models such as Green's Function Monte Carlo and No-Core Shell Model calculations. Recently, efforts have been directed towards investigating charge currents in these systems, which give rise to magnetic moments and $M1$ transition rates. In order to help guide such investigations, precise experimental data are required in order to differentiate between different theoretical predictions. We have performed a new measurement to precisely determine the excited-state lifetimes of $^{7,8}$Li in order to constrain the $B(M1)$ transition rates in these nuclei. The experiment was performed at TRIUMF using TIGRESS, populating excited states through $(d,p)$ reactions in inverse kinematics. The lifetimes were determined using the Doppler Shift Attenuation Method. Preliminary results will be presented.