On possible lower bounds for the direct detection rate of SUSY Dark Matter

One can expect accessible lower bounds for dark matter detection rate due to restrictions on masses of the SUSY-partners. To explore this correlation one needs a new-generation large-mass detector. The absolute lower bound for detection rate can naturally be due to spin-dependent interaction. Aimed at detecting dark matter with sensitivity higher than $10^{-5}$ event/day/kg an experiment should have a non-zero-spin target. Perhaps, the best is to create a GENIUS-like detector with both Ge-73 (high spin) and Ge-76 nuclei.Comment: latex, 5 pages, 3 figures. Talk given at the III International Conference on Non-accelerator New Physics (NANP'01), Dubna, 19--23 June, 200

Direct Search for Dark Matter - Striking the Balance - and the Future

Weakly Interacting Massive Particles (WIMPs) are among the main candidates for the relic dark matter (DM). The idea of the direct DM detection relies on elastic spin-dependent (SD) and spin-independent (SI) interaction of WIMPs with target nuclei. In this review paper the relevant formulae for WIMP event rate calculations are collected. For estimations of the WIMP-proton and WIMP-neutron SD and SI cross sections the effective low-energy minimal supersymmetric standard model is used. The traditional one-coupling-dominance approach for evaluation of the exclusion curves is described. Further, the mixed spin-scalar coupling approach is discussed. It is demonstrated, taking the high-spin Ge-73 dark matter experiment HDMS as an example, how one can drastically improve the sensitivity of the exclusion curves within the mixed spin-scalar coupling approach, as well as due to a new procedure of background subtraction from the measured spectrum. A general discussion on the information obtained from exclusion curves is given. The necessity of clear WIMP direct detection signatures for a solution of the dark matter problem, is pointed out.Comment: LaTeX, 49 pages, 14 figures, 185 reference

SUSY spectrum constraints on direct dark matter detection

We perform an investigation of the MSSM parameter space at the Fermi scale taking into account available accelerator, non-accelerator and cosmological constraints. Extra assumptions about upper bounds for some of the SUSY particles are also imposed. We show that a non-observation of the SUSY dark matter candidates with a high-accuracy dark matter detector, such as Ge-73, under above-mentioned assumptions can exclude large domains of the MSSM parameter space and, for instance, can make especially desirable collider search for light SUSY charged Higgs boson.Comment: latex, 13 pages, 6 figures, modified version to be published in Phys. Rev.

On the direct search for spin-dependent WIMP interactions

We examine the current directions in the search for spin-dependent dark matter. We discover that, with few exceptions, the search activity is concentrated towards constraints on the WIMP-neutron spin coupling, with significantly less impact in the WIMP-proton sector. We review the situation of those experiments with WIMP-proton spin sensitivity, toward identifying those capable of reestablishing the balance.Comment: 7 pages, 4 figure

A Large Scale Double Beta and Dark Matter Experiment: GENIUS

The recent results from the HEIDELBERG-MOSCOW experiment have demonstrated the large potential of double beta decay to search for new physics beyond the Standard Model. To increase by a major step the present sensitivity for double beta decay and dark matter search much bigger source strengths and much lower backgrounds are needed than used in experiments under operation at present or under construction. We present here a study of a project proposed recently, which would operate one ton of 'naked' enriched GErmanium-detectors in liquid NItrogen as shielding in an Underground Setup (GENIUS). It improves the sensitivity to neutrino masses to 0.01 eV. A ten ton version would probe neutrino masses even down to 10^-3 eV. The first version would allow to test the atmospheric neutrino problem, the second at least part of the solar neutrino problem. Both versions would allow in addition significant contributions to testing several classes of GUT models. These are especially tests of R-parity breaking supersymmetry models, leptoquark masses and mechanism and right-handed W-boson masses comparable to LHC. The second issue of the experiment is the search for dark matter in the universe. The entire MSSM parameter space for prediction of neutralinos as dark matter particles could be covered already in a first step of the full experiment - with the same purity requirements but using only 100 kg of 76Ge or even of natural Ge - making the experiment competitive to LHC in the search for supersymmetry. The layout of the proposed experiment is discussed and the shielding and purity requirements are studied using GEANT Monte Carlo simulations. As a demonstration of the feasibility of the experiment first results of operating a 'naked' Ge detector in liquid nitrogen are presented.Comment: 22 pages, 12 figures, see also http://pluto.mpi-hd.mpg.de/~betalit/genius.htm

Higgs Bosons and the Indirect Search for WIMPs

We investigated the contribution of the MSSM Higgs bosons produced in the neutralino annihilation in the Earth and Sun to the total WIMPs detection signals. We found that this contribution is very important and results in a lower bound for the muon flux from the Sun of 10^{-7} - 10^{-8} m^{-2} yr^{-1} for neutralinos heavier than 200 GeV. We noticed that due to the SUSY charged Higgs bosons one can expect an energetic tau neutrino flux from the Sun at a level of 10^2 m^{-2} yr^{-1}.Comment: 10 pages, 4 figures. Talk given at Dark2000, Heidelberg, Germany, 10-15 July, 200

One needs positive signatures for detection of Dark Matter

One believes there is huge amount of Dark Matter particles in our Galaxy which manifest themselves only gravitationally. There is a big challenge to prove their existence in a laboratory experiment. To this end it is not sufficient to fight only for the best exclusion curve, one has to see an annual recoil spectrum modulation --- the only available positive direct dark matter detection signature. A necessity to measure the recoil spectra is stressed.Comment: 16 pages, 1 figure. arXiv admin note: substantial Appendix text overlap with arXiv:0806.3917; missed acknowledge is added onl