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

Expected Performance of CryoArray

WIMP-nucleon cross sections below 10^(-9) pb may be probed by ton-scale experiments with low thresholds and background rates ~20 events per year. An array of cryogenic detectors ("CryoArray") could perform well enough to reach this goal. Sufficient discrimination and background suppression of photons has already been demonstrated. Reduction of neutron backgrounds may be achieved by siting the experiment deep enough. Removal of the surface-electron backgrounds alone has not yet been demonstrated, but the reductions required even for this troublesome background are quite modest and appear achieveable.Comment: 4 pages, 2 figures. Talk at DM2002 Conference, Marina del Rey, CA, Feb 20-22, 200

Nucleon scattering with higgsino and wino cold dark matter

Neutralinos that are mostly wino or higgsino are shown to be compatible with the recent DAMA annual modulation signal. The nucleon scattering rates for these dark matter candidates are typically an order of magnitude above the oft-considered bino. Although thermal evolution of higgsino and wino number densities in the early universe implies that they are not viable dark matter candidates, non-thermal sources, such as from gravitino or moduli decay in anomaly mediated supersymmetry breaking, suggest that they can be the dominant source of cold dark matter. Their stealthiness at high energy colliders gives even more impetus to analyze nucleon scattering detection methods. We also present calculations for their predicted scattering rate with Germanium detectors, which have yet to see evidence of WIMP scattering.Comment: 16 pages, LaTex, 4 figures, uses feynMF, minor changes made for PRD publicatio

Stable Neutral Fermi Ball

Fermi Ball is a kind of nontopological soliton with fermions trapped in its domain wall, and is suggested to arises from the spontaneous symmetry breaking of the approximate $Z_2$ symmetry in the early universe. We find that the neutral thin-wall Fermi Ball is stable in the limited region of the scalar self-coupling constant $\lambda$ and the Yukawa coupling constant $G$. We find that the Fermi Ball is stabilized due to the curvature effect of the domain wall caused by the fermion sector. We also discuss whether such stable Fermi Balls may contribute to the cold dark matter.Comment: 18 pages in RevTeX, 5 figure

Generalized Analysis of Weakly-Interacting Massive Particle Searches

We perform a generalized analysis of data from WIMP search experiments for point-like WIMPs of arbitrary spin and general Lorenz-invariant WIMP-nucleus interaction. We show that in the non-relativistic limit only spin-independent (SI) and spin-dependent (SD) WIMP-nucleon interactions survive, which can be parameterized by only five independent parameters. We explore this five-dimensional parameter space to determine whether the annual modulation observed in the DAMA experiment can be consistent with all other experiments. The pure SI interaction is ruled out except for very small region of parameter space with the WIMP mass close to 50 GeV and the ratio of the WIMP-neutron to WIMP-proton SI couplings $-0.77\le f_n/f_p\le -0.75$. For the predominantly SD interaction, we find an upper limit to the WIMP mass of about 18 GeV, which can only be weakened if the constraint stemming from null searches for energetic neutrinos from WIMP annihilation the Sun is evaded. None of the regions of the parameter space that can reconcile all WIMP search results can be easily accommodated in the minimal supersymmetric extension of the standard model.Comment: 27 pages, 3 figure

GENIUS-TF: a test facility for the GENIUS project

GENIUS is a proposal for a large scale detector of rare events. As a first step of the experiment, a small test version, the GENIUS test facility, will be build up at the Laboratorio Nazionale del Gran Sasso (LNGS). With about 40 kg of natural Ge detectors operated in liquid nitrogen, GENIUS-TF could exclude (or directly confirm) the DAMA annual modulation signature within about two years of measurement.Comment: 14 pages, latex, 5 figures, 3 tables; submitted to Astroparticle Physic

Search for Supersymmetric Dark Matter with Superfluid He3 (MACHe3)

MACHe3 (MAtrix of Cells of superfluid He3) is a project of a new detector for direct Dark Matter search, using superfluid He3 as a sensitive medium. This paper presents a phenomenological study done with the DarkSUSY code, in order to investigate the discovery potential of this project of detector, as well as its complementarity with existing and planned devices.Comment: 15 pages, 5 figures, submitted to Phys. Letters B, minor changes in the tex

Astroparticle Aspects of Supersymmetry

After recalling the motivations for expecting supersymmetry to appear at energies below 1 TeV, the reasons why the lightest supersymmetric particle is an ideal candidate for cold dark matter are reviewed from a historical perspective. Recent calculations of the relic density including coannihilations and rapid annihilations through direct-channel Higgs boson poles are presented. The experimental constraints from LEP and elsewhere on supersymmetric dark matter are reviewed, and the prospects for its indirect or direct detection are mentioned. The potential implications of a Higgs boson weighing about 115 GeV and the recent measurement of the anomalous magnetic moment of the muon are summarized.Comment: 12 pages, 10 eps figures, invited plenary talk at conference on 30 Years Of Supersymmetry, Oct. 2000, Minneapolis, Minnesot

WIMP Annual Modulation with Opposite Phase in Late-Infall Halo Models

We show that in the late-infall model of our galactic halo by P. Sikivie the expected phase of the annual modulation of a WIMP halo signal in direct detection experiments is opposite to the one usually expected. If a non-virialized halo component due to the infall of (collisionless) dark matter particles cannot be rejected, an annual modulation in a dark matter signal should be looked for by experimenters without fixing the phase a-priori. Moreover, WIMP streams coming to Earth from directions above and below the galactic plane should be expected, with a characteristic pattern of arrival directions.Comment: 15 pages, 5 figure

Determination of the String Scale in D-Brane Scenarios and Dark Matter Implications

We analyze different phenomenological aspects of D-brane constructions. First, we obtain that scenarios with the gauge group and particle content of the supersymmetric standard model lead naturally to intermediate values for the string scale, in order to reproduce the value of gauge couplings deduced from experiments. Second, the soft terms, which turn out to be generically non universal, and Yukawa couplings of these scenarios are studied in detail. Finally, using these soft terms and the string scale as the initial scale for their running, we compute the neutralino-nucleon cross section. In particular we find regions in the parameter space of D-brane scenarios with cross sections in the range of $10^{-6}$--$10^{-5}$ pb, i.e. where current dark matter experiments are sensitive. For instance, this can be obtained for $\tan\beta > 5$.Comment: Figures improved, misprints corrected, results basically unchange