Compatibility of DAMA/LIBRA dark matter detection with other searches

Abstract

The DAMA/NaI and DAMA/LIBRA annual modulation data, which may be interpreted as a signal for the existence of weakly interacting dark matter (WIMPs) in our galactic halo, are examined in light of null results from other experiments: CDMS, XENON10, CRESST I, CoGeNT, TEXONO, and Super-Kamiokande (Su-perK). We use the energy spectrum of the combined DAMA modulation data given in 36 bins, and include the effect of channeling. Several statistical tools are implemented in our study: likelihood ratio with a global fit and with raster scans in the WIMP mass and goodness-of-fit (g.o.f.). These approaches allow us to differentiate between the preferred (global best fit) and allowed (g.o.f.) parameter regions. It is hard to find WIMP masses and couplings consistent with all existing data sets; the surviving regions of parameter space are found here. For spin-independent (SI) interactions, the best fit DAMA regions are ruled out to the 3σ C.L., even with channeling taken into account. However, for WIMP masses of ∼8 GeV some parameters outside these regions still yield a moderately reasonable fit to the DAMA data and are compatible with all 90% C.L. upper limits from negative searches, when channeling is included. For spin-dependent (SD) interactions with proton-only couplings, a range of masses below 10 GeV is compatible with DAMA and other experiments, with and without channeling, when SuperK indirect detection constraints are included; without the SuperK constraints, masses as high as ∼20 GeV are compatible. For SD neutron-only couplings we find no parameters compatible with all the experiments. Mixed SD couplings are examined: e.g. ∼8 GeV mass WIMPs with a n = ±a p are found to be consistent with all experiments. In short, there are surviving regions at low mass for both SI and SD interactions; if indirect detection limits are relaxed, some SD proton-only couplings at higher masses also survive.

Unitarity and monojet bounds on models for DAMA, CoGeNT, and CRESST-II

“…All bounds are derived under the assumption that the quark-DM interaction O remains contact at LHC energies and with universal quark coupling. For reference we include the DAMA 3σ [1,32], CoGeNT 90% CL [2], and CRESST-II 1σ and 2σ preferred regions [3] as well as the 90% CL XENON-100 bound [33].…”

Complex scalar dark mattervis-à-visCoGeNT, DAMA/LIBRA, and XENON100

“…The boundary of the favored signal region is dependent on channeling [19][20][21], but it has recently been argued that channeling effects are unimportant [22]. In our study we consider the DAMA/LIBRA boundaries without channeling from Ref.…”

Highlights from Super-Kamiokande

“…SK is possible to search WIMP signal by looking for such neutrino events from the Sun. Recently some direct dark matter experiments, such as DAMA/LIBRA [16,17], reported positive results in the low energy WIMP mass region around 10 GeV. We have improved our analysis to search for WIMP signal for such low energy region.…”