Influence of NaI background and mass on testing the DAMA modulation

Abstract

NaI experiments should be sensitive to the same DM-SM interactions proposed to explain the observed DAMA modulation. As such, they are often called a ‘model independent’ test of the signal. While the same signal will be produced at all NaI detectors, the ability to observe it is strongly dependent on the experimental set up - in particular the mass and background of the target. We present here a study on how changes to these values influence the ability of a detector to observe a characteristic DM modulation. We consider both the standard elastic, spin independent WIMP and a model independent analysis assuming exactly the modulation signal observed by DAMA (i.e., making no assumptions about the particle interaction model producing this signal), and find that in both cases a lower background is favoured over a higher exposure mass (based on currently achievable levels).