Temporal distortion of annual modulation at low recoil energies

We show that the main features of the annual modulation of the signal expected in a WIMP direct detection experiment, i.e. its sinusoidal dependence with time, the occurrence of its maxima and minima during the year and (under some circumstances) even the one-year period, may be affected by relaxing the isothermal sphere hypothesis in the description of the WIMP velocity phase space. The most relevant effect is a distortion of the time-behaviour at low recoil energies for anisotropic galactic halos. While some of these effects turn out to be relevant at recoil energies below the current detector thresholds, some others could already be measurable, although some degree of tuning between the WIMP mass and the experimental parameters would be required. Either the observation or non-observation of these effects could provide clues on the phase space distribution of our galactic halo.Comment: 4 pages, 4 figures, typeset with ReVTeX4. The paper may also be found at http://www.to.infn.it/~fornengo/papers/distortion.ps.g

New results from DAMA/LIBRA

DAMA/LIBRA is running at the Gran Sasso National Laboratory of the I.N.F.N.. Here the results obtained with a further exposure of 0.34 ton x yr are presented. They refer to two further annual cycles collected one before and one after the first DAMA/LIBRA upgrade occurred on September/October 2008. The cumulative exposure with those previously released by the former DAMA/NaI and by DAMA/LIBRA is now 1.17 ton x yr, corresponding to 13 annual cycles. The data further confirm the model independent evidence of the presence of Dark Matter (DM) particles in the galactic halo on the basis of the DM annual modulation signature (8.9 sigma C.L. for the cumulative exposure). In particular, with the cumulative exposure the modulation amplitude of the single-hit events in the (2 -- 6) keV energy interval measured in NaI(Tl) target is (0.0116 +- 0.0013) cpd/kg/keV; the measured phase is (146 +- 7) days and the measured period is (0.999 +- 0.002) yr, values well in agreement with those expected for the DM particles.Comment: presented at the Int. Conf. Beyond the Standard Models of Particle Physics, Cosmology and Astrophysics (BEYOND 2010), 1-6 February 2010, Cape Town, South Afric

Dark Matter candidate in a Heavy Higgs Model - Direct Detection Rates

We investigate direct detection rates for Dark Matter candidates arise in a $SU(2)_L\times U(1)_Y$ with an additional doublet Higgs proposed by Barbieri, Hall and Rychkov. We refer this model as `Heavy Higgs Model'. The Standard Model Higgs mass comes out in this model very heavy adopting the few per cent chance that there is no Higgs boson mass below 200 GeV. The additional Higgs boson develops neither any VEV due to the choice of coefficient of the scalar potential of the model nor it has any coupling with fermions due to the incorporation of a discrete parity symmetry. Thus, the neutral components of the extra doublet are stable and can be considered as probable candidate of Cold Dark Matter. We have made calculations for three different types of Dark Matter experiments, namely, $^{76}$Ge (like GENIUS), DAMA (NaI) and XENON ($^{131}$Xe). Also demonstrated the annual variation of Dark Matter detection in case of all three detectors considered.Comment: 10 pages, 9 figures, figures unchanged, text modified, version to appear in Mod. Phys. Lett.

Cold Dark Matter and Neutralinos

Neutralinos are natural candidates for cold dark matter in many realizations of supersymmetry. We briefly review our recent results in the evaluation of neutralino relic abundance and direct detection rates in a class of supergravity models.Comment: 4 pages, 4 figures, uses espcrc2.sty. Proc. of "Sources and detection of dark matter and dark energy in the Universe (DM2002)". The version on the archive has low-resolution figures. The paper with high-resolution figures can be found at http://www.to.infn.it/~fornengo/proceedings/marinadelrey02.ps.gz or through http://www.to.infn.it/astropart

Results on Dark Matter and beta beta decay modes by DAMA at Gran Sasso

DAMA is an observatory for rare processes and it is operative deep underground at the Gran Sasso National Laboratory of the I.N.F.N. (LNGS). Here some arguments will be presented on the investigation on dark matter particles by annual modulation signature and on some of the realized double beta decay searches.Comment: Contributed paper to Neutrinoless Double Beta Decay (NDBD07), Ahmedabad (India), February 200

Inelastic Dark Matter at DAMA, CDMS and Future Experiments

The DAMA annual modulation signature, interpreted as evidence for a spin-independent WIMP coupling, seems in conflict with null results from CDMS. However, in models of ``inelastic dark matter'', the experiments are compatible. Inelastic dark matter can arise in supersymmetric theories as the real component of a sneutrino mixed with a singlet scalar. In contrast with ordinary sneutrino dark matter, such particles can satisfy all experimental constraints while giving the appropriate relic abundance. We discuss the modifications to the signal seen at DAMA, in particular noting the strong suppression of low energy events in both modulated and unmodulated components. We discuss future experiments, with emphasis on distinguishing inelastic dark matter from ordinary dark matter, and stressing the significance of experiments with heavy target nuclei, such as xenon and tungsten.Comment: 4 pages; to appear in the proceedings of 5th International UCLA Symposium on Sources and Detection of Dark Matter and Dark Energy in the Universe (DM 2002), Marina del Rey, California, 20-22 Feb 200

First results from dark matter search experiment with LiF bolometer at Kamioka Underground Laboratory

Tokyo group has performed first underground dark matter search experiment in 2001 through 2002 at Kamioka Observatory(2700m.w.e). The detector is eight LiF bolometers with total mass 168g aiming for the direct detection of WIMPs via spin-dependent interaction. With a total exposure of 4.1 kg days, we derived the limits in the a_p-a_n (WIMP-nucleon couplings) plane and excluded a large part of the parameter space allowed by the UKDMC experiment.Comment: 15 pages, 5 figure

Technical aspects in dark matter investigations

Some theoretical and experimental aspects regarding the direct dark matter field are mentioned. In particular some arguments, which play a relevant role in the evaluation of model dependent interpretations of experimental results and in comparisons, are shortly addressed.Comment: Proceedings of TAUP 2011 Conferenc

Implications of the DAMA/NaI and CDMS experiments for mirror matter-type dark matter

We re-analyse the implications of the DAMA/NaI experiment for mirror matter-type dark matter, taking into account information from the energy dependence of the DAMA annual modulation signal. This is combined with the null results from the CDMS experiment, leading to fairly well defined allowed regions of parameter space. The allowed regions of parameter space will be probed in the near future by the DAMA/LIBRA, CDMS, and other experiments, which should either exclude or confirm this explanation of the DAMA/NaI annual modulation signal. In particular, we predict that the CDMS experiments should find a positive signal around the threshold recoil energy region, E_R < 15 keV in the near future.Comment: about 15 pages, Some changes to the tex