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Mass loss remains a major uncertainty in stellar modelling. In low-massstars, mass loss is most significant on the red giant branch (RGB), and willimpact the star's evolutionary path and final stellar remnant. Directlymeasuring the mass difference of stars in various phases of evolutionrepresents one of the best ways to quantify integrated mass loss. Globularclusters (GCs) are ideal objects for this. M4 is currently the only GC forwhich asteroseismic data exists for stars in multiple phases of evolution.Using K2 photometry, we report asteroseismic masses for 75 red giants in M4,the largest seismic sample in a GC to date. We find an integrated RGB mass lossof $\Delta\bar{M} = 0.17 \pm 0.01 ~\mathrm{M}_{\odot}$, equivalent to aReimers' mass-loss coefficient of $\eta_R = 0.39$. Our results for initialmass, horizontal branch mass, $\eta_R$, and integrated RGB mass loss showremarkable agreement with previous studies, but with higher precision usingasteroseismology. We also report the first detections of solar-likeoscillations in early asymptotic giant branch (EAGB) stars in GCs. We find anaverage mass of $\bar{M}_{\text{EAGB}}=0.54 \pm 0.01 ~\mathrm{M}_{\odot}$,significantly lower than predicted by models. This suggestslarger-than-expected mass loss on the horizontal branch. Alternatively, itcould indicate unknown systematics in seismic scaling relations for the EAGB.We discover a tentative mass bi-modality in the RGB sample, possibly due to themultiple populations. In our red horizontal branch sample, we find a massdistribution consistent with a single value. We emphasise the importance ofseismic studies of GCs since they could potentially resolve major uncertaintiesin stellar theory.

Integrated Mass Loss of Evolved Stars in M4 using Asteroseismology