DAMA Dark Matter Detection Compatible with Other Searches

Abstract

We present two examples of velocity distributions for light dark matter particles that reconcile the annual modulation signal observed by DAMA with all other negative results from dark matter searches. They are: (1) a conventional Maxwellian distribution for particle masses of 6 to 9 GeV; (2) a dark matter stream coming from the general direction of Galactic rotation (not the Sagittarius stream). Our idea is based on having a signal in Na, instead of I, in DAMA, and can be tested in the immediate future by CDMS-II (using Si) and CRESST-II (using O).

Figures (2)

• Figure 1: Stream heliocentric speed $v_{\rm str}$ (here assumed to arrive from ecliptic latitude $\beta_{\rm str}=30^\circ$ and ecliptic longitude $\lambda_{\rm str}=340^\circ$) vs. WIMP mass $m$. The hatched region is compatible with DAMA, CDMS, EDELWEISS, and CRESST. Which experiment limits the compatible region is indicated along its edges. Also marked are the speed above which the stream is extragalactic (dashed horizontal line), and the threshold speeds $v_{\rm th}$ of several experiments and target nuclei.
• Figure 2: Region of WIMP-proton cross section $\sigma_{\rm p}$ resulting from our study vs. WIMP mass $m$ (cross-hatched region: without stream; hatched region: with stream and velocity cuts as shown). Also limits from DAMA/NaI-96, CRESST-I and II, and CDMS-I and II (see Table 1).