Search for An Annual Modulation in Three Years of CoGeNT Dark Matter Detector Data
Weakly Interacting Massive Particles (WIMPs) are well-established dark matter candidates. WIMP interactions with sensitive detectors are expected to display a characteristic annual modulation in rate. We release a dataset spanning 3.4 years of operation from a low-background germanium detector, designed to search for this signature. A previously reported modulation persists, concentrated in a region of the energy spectrum populated by an exponential excess of unknown origin. Its phase and period agree with phenomenological expectations, but its amplitude is a factor $\sim$4-7 larger than predicted for a standard WIMP galactic halo. We consider the possibility of a non-Maxwellian local halo velocity distribution as a plausible explanation, able to help reconcile recently reported WIMP search anomalies.
- Aalseth, CE; Barbeau, PS; Colaresi, J; Collar, JI; Leon, JD; Fast, JE; Fields, NE; Hossbach, TW; Knecht, A; Kos, MS; Marino, MG; Miley, HS; Miller, ML; Orrell, JL; Yocum, KM
- January 14, 2014