Dark matter direct detection rate in a generic model with micrOMEGAs_2.2

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 (SuperK). 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 an = ±ap 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 high masses also survive.

https://iopscience.iop.org/article/10.1088/1475-7516/2009/04/010/pdf

Compatibility of DAMA/LIBRA dark matter detection with other searches

In recent decades, several detector technologies have been developed with the quest to directly detect dark matter interactions and to test one of the most important unsolved questions in modern physics. The sensitivity of these experiments has improved with a tremendous speed due to a constant development of the detectors and analysis methods, proving uniquely suited devices to solve the dark matter puzzle, as all other discovery strategies can only indirectly infer its existence. Despite the overwhelming evidence for dark matter from cosmological indications at small and large scales, clear evidence for a particle explaining these observations remains absent. This review summarises the status of direct dark matter searches, focusing on the detector technologies used to directly detect a dark matter particle producing recoil energies in the keV energy scale. The phenomenological signal expectations, main background sources, statistical treatment of data and calibration strategies are discussed.

https://iopscience.iop.org/article/10.1088/0954-3899/43/1/013001/pdf

Dark matter direct-detection experiments

We review recent work on the possibility of a varying speed of light (VSL). We start by discussing the physical meaning of a varying-c, dispelling the myth that the constancy of c is a matter of logical consistency. We then summarize the main VSL mechanisms proposed so far: hard breaking of Lorentz invariance; bimetric theories (where the speeds of gravity and light are not the same); locally Lorentz invariant VSL theories; theories exhibiting a colour-dependent speed of light; varying-c induced by extra dimensions (e.g. in the brane-world scenario); and field theories where VSL results from vacuum polarization or CPT violation. We show how VSL scenarios may solve the cosmological problems usually tackled by inflation, and also how they may produce a scale-invariant spectrum of Gaussian fluctuations, capable of explaining the WMAP data. We then review the connection between VSL and theories of quantum gravity, showing how 'doubly special' relativity has emerged as a VSL effective model of quantum space?time, with observational implications for ultra-high energy cosmic rays (UHECRs) and gamma ray bursts. Some recent work on the physics of 'black' holes and other compact objects in VSL theories is also described, highlighting phenomena associated with spatial (as opposed to temporal) variations in c. Finally, we describe the observational status of the theory. The evidence is currently slim?redshift dependence in the atomic fine structure, anomalies with UHECRs, and (to a much lesser extent) the acceleration of the universe and the WMAP data. The constraints (e.g. those arising from nucleosynthesis or geological bounds) are tight but not insurmountable. We conclude with the observational predictions of the theory and the prospects for its refutation or vindication.

https://iopscience.iop.org/article/10.1088/0034-4885/66/11/R04/pdf

New varying speed of light theories

Main arguments on the Dark Matter particle direct detection approach are addressed on the basis of the work and of the results of the about 100 kg highly radiopure NaI(Tl) DAMA experiment (DAMA/NaI), which has been operative at the Gran Sasso National Laboratory of the I.N.F.N. for more than one decade, including the preparation. The effectiveness of the WIMP model independent annual modulation signature is pointed out by discussing the results obtained over 7 annual cycles (107731 kg day total exposure); the WIMP presence in the galactic halo is strongly supported at 6.3 standard deviation C.L. The complexity of the corollary model dependent quests for a candidate particle is also addressed and several of the many possible scenarios are examined.

Dark matter search

We perform nuclear shell model calculations of the neutralino-nucleus cross section for several nuclei in the A=127 region. Each of the four nuclei considered is a primary target in a direct dark matter detection experiment. The calculations are valid for all relevant values of the momentum transfer. Our calculations are performed in the 3s2d1g{sub 7/2}1h{sub 11/2} model space using extremely large bases, allowing us to include all relevant correlations. We also study the dependence of the nuclear response upon the assumed nuclear Hamiltonian and find it to be small. We find good agreement with the observed magnetic moment as well as other obervables for the four nuclei considered: {sup 127}I, {sup 129,131}Xe, and {sup 125}Te. {copyright} {ital 1997} {ital The American Physical Society}

Spin-dependent neutralino-nucleus scattering for A ∼ 127 nuclei

We calculate spin-dependent cross sections for the scattering from mica of hypothetical weakly interacting dark-matter particles such as neutralinos. The most abundant odd-A isotopes in mica, $^{27}\mathrm{Al}$ and $^{39}\mathrm{K}$, require different shell-model treatments. The calculated cross sections will allow the interpretation of ongoing experiments that look for tracks due to the interaction of dark-matter particles with nuclei in ancient mica.

Response of Mica to Weakly Interacting Massive Particles

We use the experimental limit on the interference of M1 and E2 multipoles in the γ decay of 57Fe to bound the time-reversal-violating parity-conserving ρNN vertex. Our approach is a large-basis shell-model calculation of the interference. We find an upper limit on the parameter g¯ρ, the relative strength of the T-violating ρNN vertex, of close to 10^(-2), a value similar to the best limits from other experiments.

https://arxiv.org/pdf/nucl-th/9512013.pdf

M. T. Ressell

Papers

Spin-dependent neutralino-nucleus scattering for A ∼ 127 nuclei

Response of Mica to Weakly Interacting Massive Particles

Limit on T-violating P-conserving rho NN interaction from the gamma decay of 57Fe.