First search for a dark matter annual modulation signal with NaI(Tl) in the Southern Hemisphere by DM-Ice17

The first search for a dark matter annual modulation signal with NaI(Tl) target material in the Southern Hemisphere conducted with the DM-Ice17 experiment is presented. DM-Ice17 consists of 17 kg of NaI(Tl) scintillating crystal under 2200 m.w.e. overburden of Antarctic glacial ice. The analysis presented here utilizes a 60.8 kg yr exposure. While unable to exclude the signal reported by DAMA/LIBRA, the DM-Ice17 data are consistent with no modulation in the energy range of 4-20 keV, providing the strongest limits on WIMP candidates from a direct detection experiment located in the Southern Hemisphere. Additionally, the successful deployment and stable operation of 17 kg of NaI(Tl) crystal over 3.5 years establishes the South Pole ice as a viable location for future underground, low-background experiments.