9 research outputs found
Lower limit on the neutralino mass in the general MSSM
We discuss constraints on SUSY models with non-unified gaugino masses and R_P
conservation. We derive a lower bound on the neutralino mass combining the
direct limits from LEP, the indirect limits from gmuon, bsgamma, Bsmumu and the
relic density constraint from WMAP. The lightest neutralino (mneutralino=6GeV)
is found in models with a light pseudoscalar with MA<200GeV and a large value
for . Models with heavy pseudoscalars lead to mneutralino>18(29)GeV
for . We show that even a very conservative bound from the
muon anomalous magnetic moment can increase the lower bound on the neutralino
mass in models with mu<0 and/or large values of . We then examine
the potential of the Tevatron and the direct detection experiments to probe the
SUSY models with the lightest neutralinos allowed in the context of light
pseudoscalars with high . We also examine the potential of an e+e-
collider of 500GeV to produce SUSY particles in all models with neutralinos
lighter than the W. In contrast to the mSUGRA models, observation of at least
one sparticle is not always guaranteed.Comment: 37 pages, LateX, 16 figures, paper with higher resolution figures
available at
http://wwwlapp.in2p3.fr/~boudjema/papers/bound-lsp/bound-lsp.htm
Muon-induced background in the EDELWEISS dark matter search
A dedicated analysis of the muon-induced background in the EDELWEISS dark
matter search has been performed on a data set acquired in 2009 and 2010. The
total muon flux underground in the Laboratoire Souterrain de Modane (LSM) was
measured to be \,muons/m/d. The
modular design of the muon-veto system allows the reconstruction of the muon
trajectory and hence the determination of the angular dependent muon flux in
LSM. The results are in good agreement with both MC simulations and earlier
measurements. Synchronization of the muon-veto system with the phonon and
ionization signals of the Ge detector array allowed identification of
muon-induced events. Rates for all muon-induced events and of WIMP-like events were extracted. After
vetoing, the remaining rate of accepted muon-induced neutrons in the
EDELWEISS-II dark matter search was determined to be at 90%\,C.L. Based on
these results, the muon-induced background expectation for an anticipated
exposure of 3000\,\kgd\ for EDELWEISS-3 is
events.Comment: 21 pages, 16 figures, Accepted for publication in Astropart. Phy
Calibration of the EDELWEISS Cryogenic Heat-and-ionisation Germanium Detectors for Dark Matter Search
Several aspects of the analysis of the data obtained with the cryogenic
heat-and-ionisation Ge detectors used by the EDELWEISS dark matter search
experiment are presented. Their calibration, the determination of their energy
threshold, fiducial volume and nuclear recoil acceptance are detailed.Comment: 27 pages, Latex, 11 figures. Submitted to NIM
Measurement of the cosmogenic activation of germanium detectors in EDELWEISS-III
International audienceWe present a measurement of the cosmogenic activation in the germanium cryogenic detectors of the EDELWEISS III direct dark matter search experiment. The decay rates measured in detectors with different exposures to cosmic rays above ground are converted into production rates of different isotopes. The measured production rates in units of nuclei/kg/day are 82 21 for H, 2.8 0.6 for V, 4.6 0.7 for Fe, and 106 13 for Zn. These results are the most accurate for these isotopes. A lower limit on the production rate of Ge of 74 nuclei/kg/day is also presented. They are compared to model predictions present in literature and to estimates calculated with the ACTIVIA code
From Edelweiss-I to Edelweiss-II
6 pages, 3 figures, to appear in the Proceedings of the 5th International Workshop on the Identification of Dark Matter (IDM2004), eds. N.Spooner and V.Kudryavstev - ManoirThe EDELWEISS experiment is a Direct Dark Matter search using 320 g heat-and-ionization Ge cryogenic detectors. The final results obtained by the EDELWEISS-I stage corresponding to a total of 62 kg.day are presented. The status of EDELWEISS-II, involving in a first phase ~10 kg of detecors and aiming to gain two orders of magnitude in sensitivity, is also described
First results of the EDELWEISS-II WIMP search using Ge cryogenic detectors with interleaved electrodes
14 pages, 3 figures. Submitted to Phys Lett. BThe EDELWEISS-II collaboration has performed a direct search for WIMP dark matter with an array of ten 400 g heat-and-ionization cryogenic detectors equipped with interleaved electrodes for the rejection of near-surface events. Six months of continuous operation at the Laboratoire Souterrain de Modane have been achieved. The observation of one nuclear recoil candidate above 20 keV in an effective exposure of 144 kgd is interpreted in terms of limits on the cross-section of spin-independent interactions of WIMPs and nucleons. A cross-section of 1.0x10^-7 pb is excluded at 90%CL for a WIMP mass of 80 GeV/c2. This result demonstrates for the first time the very high background rejection capabilities of these simple and robust detectors in an actual WIMP search experiment