Lowering the Threshold in the DAMA Dark Matter Search

Abstract

The DAMA experiment searches for Weakly Interacting Massive Particle (WIMP) dark matter via its expected but rare interactions within the detector, where the interaction rates will modulate throughout the year due to the orbital motion of the Earth. Over the course of more than 10 years of operation, DAMA has indeed detected a strong modulation in the event rate above the detector threshold of 2 keVee. Under standard assumptions regarding the dark matter halo and WIMP interactions, this signal is consistent with that expected of WIMPs of two different approximate masses: ~ 10 GeV and ~ 70 GeV. We examine how a lower threshold, allowed by recent upgrades to the DAMA detector, may shed light on this situation. We find that the lower threshold data should rule out one of the two mass ranges for spin-independent couplings (in the worst case, disfavoring one of the masses by still more than 2.6$\sigma$) and is likely, though not certain, to do the same for spin-dependent couplings. Furthermore, the data may indicate whether the interaction is predominantly spin-independent or spin-dependent in some cases. Our findings illustrate the importance of a low threshold in modulation searches.

26 pages, 7 figures. v2: expanded discussion, added references

References in corpus (15)

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• Trigonometric Parallaxes of Massive Star Forming Regions: VI. Galactic Structure, Fundamental Parameters and Non-Circular Motions
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• The RAVE Survey: Constraining the Local Galactic Escape Speed
• Results from a Low-Energy Analysis of the CDMS II Germanium Data
• The DAMA/LIBRA apparatus
• Galactic masers and the Milky Way circular velocity
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• Dark Matter investigation by DAMA at Gran Sasso
• DAMA and WIMP dark matter
• Nuclear spin structure in dark matter search: The finite momentum transfer limit
• Using the Energy Spectrum at DAMA/LIBRA to Probe Light Dark Matter
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Cited by in corpus (12)

• The Dark Z' Portal: Direct, Indirect and Collider Searches
• The impact of baryons on the direct detection of dark matter
• Model-independent comparison of annual modulation and total rate with direct detection experiments
• LUX likelihood and limits on spin-independent and spin-dependent WIMP couplings with LUXCalc
• Time-dependent rate of multicomponent dark matter: Reproducing the DAMA/LIBRA phase-2 results
• Halo-independent tests of dark matter annual modulation signals
• Direct Detection Anomalies in light of $Gaia$ Data
• GeV WIMPs scattering off of OH impurities cannot explain the DAMA signal
• Examining the time dependence of DAMA's modulation amplitude
• Bayesian analysis of multiple direct detection experiments
• Inelastic dark matter scattering off Thallium cannot save DAMA
• DAMA annual modulation is not due to electron recoils from Plasma/Mirror Dark Matter with Kinetic Mixing