  We have analyzed high-resolution, adaptive optics (AO) HK observations of the
Arches cluster obtained with NAOS/CONICA. With a spatial resolution of 84 mas,
the cluster center is uniquely resolved. From these data the present-day mass
function (MF) of Arches is derived down to about 4 Msun. The integrated MF as
well as the core and 2nd annulus MFs are consistent with a turn-over at 6-7
Msun. This turn-over indicates severe depletion of intermediate and low-mass
stars in the Arches cluster, possibly caused by its evolution in the Galactic
Center environment. The Arches MF represents the first resolved observation of
a starburst cluster exhibiting a low-mass truncated MF. This finding has severe
implications for stellar population synthesis modelling of extragalactic
starbursts, the derivation of integrated properties such as the total mass of
star clusters in dense environments, the survival of low-mass remnants from
starburst populations, and chemical enrichment during starburst phases.
