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CDMS,
EDELWEISS Collaborations: Z. Ahmed,
D. S. Akerib,
E. Armengaud,
S. Arrenberg,
C. Augier,
C. N. Bailey,
D. Balakishiyeva,
L. Baudis,
D. A. Bauer, [......],
A. S. Torrento-Coello,
L. Vagneron,
M-A. Verdier,
R. J. Walker,
P. Wikus,
E. Yakushev,
S Yellin,
J Yoo,
B. A. Young,
J Zhang
[show abstract]
[hide abstract]
ABSTRACT: The CDMS and EDELWEISS collaborations have combined the results of their
direct searches for dark matter using cryogenic germanium detectors. The total
data set represents 614 kg.d equivalent exposure. A straightforward method of
combination was chosen for its simplicity before data were exchanged between
experiments. The results are interpreted in terms of limits on spin-independent
WIMP-nucleon cross-section. For a WIMP mass of 90 GeV/c^2, where this analysis
is most sensitive, a cross-section of 3.3 x 10^{-44} cm^2 is excluded at 90%
CL. At higher WIMP masses, the combination improves the individual limits, by a
factor 1.6 above 700 GeV/c^2. Alternative methods of combining the data provide
stronger constraints for some ranges of WIMP masses and weaker constraints for
others.
Physical Review D 05/2011; 84:011102. · 4.56 Impact Factor
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EDELWEISS Collaboration,
E. Armengaud,
C. Augier,
A. Benoît,
L. Bergé,
J. Blümer,
A. Broniatowski,
V. Brudanin,
B. Censier,
G. Chardin, [......],
S. Rozov,
V. Sanglard,
B. Schmidt,
S. Scorza,
S. Semikh,
A. S. Torrento-Coello,
L. Vagneron,
M-A. Verdier,
R. J. Walker,
E. Yakushev
[show abstract]
[hide abstract]
ABSTRACT: The EDELWEISS-II collaboration has completed a direct search for WIMP dark
matter with an array of ten 400-g cryogenic germanium detectors in operation at
the Laboratoire Souterrain de Modane. The combined use of thermal phonon
sensors and charge collection electrodes with an interleaved geometry enables
the efficient rejection of gamma-induced radioactivity as well as near-surface
interactions. A total effective exposure of 384 kg.d has been achieved, mostly
coming from fourteen months of continuous operation. Five nuclear recoil
candidates are observed above 20 keV, while the estimated background is 3.0
events. The result is interpreted in terms of limits on the cross-section of
spin-independent interactions of WIMPs and nucleons. A cross-section of
4.4x10^-8 pb is excluded at 90%CL for a WIMP mass of 85 GeV. New constraints
are also set on models where the WIMP-nucleon scattering is inelastic.
Physics Letters B 03/2011; 702:329–335. · 3.95 Impact Factor
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V. Yu. Kozlov,
E. Armengaud,
C. Augier,
A. Benoit,
L. Berge,
O. Besida,
J. Blumer,
A. Broniatowski,
V. Brudanin,
A. Chantelauze, [......],
P. Pari,
B. Paul,
S. Rozov,
V. Sanglard,
S. Scorza,
S. Semikh,
A. S. Torrento-Coello,
L. Vagneron,
M-A. Verdier,
E. Yakushev
[show abstract]
[hide abstract]
ABSTRACT: Muon-induced neutrons constitute a prominent background component in a number of low count rate experiments, namely direct searches for Dark Matter. In this work we describe a neutron detector to measure this background in an underground laboratory, the Laboratoire Souterrain de Modane. The system is based on 1 m3 of Gd-loaded scintillator and it is linked with the muon veto of the EDELWEISS-II experiment for coincident muon detection. The system was installed in autumn 2008 and passed since then a number of commissioning tests proving its full functionality. The data-taking is continuously ongoing and a count rate of the order of 1 muon-induced neutron per day has been achieved. Comment: Accepted for publication in Astroparticle Physics; 14 pages, 10 figures
Astroparticle Physics 06/2010; 34:97–105. · 3.22 Impact Factor
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S. Rozov,
E. Armengaud,
C. Augier,
L. Bergé,
A. Benoit,
O. Besida,
J. Blümer,
A. Broniatowski,
V. Brudanin,
A. Chantelauze, [......],
C. Nones,
E. Olivieri,
P. Pari,
B. Paul,
V. Sanglard,
S. Scorza,
S. Semikh,
M-A. Verdier,
L. Vagneron,
E. Yakushev
[show abstract]
[hide abstract]
ABSTRACT: This paper describes precise measurements of the thermal neutron flux in the LSM underground laboratory in proximity of the EDELWEISS-II dark matter search experiment together with short measurements at various other locations. Monitoring of the flux of thermal neutrons is accomplished using a mobile detection system with low background proportional counter filled with $^3$He. On average 75 neutrons per day are detected with a background level below 1 count per day (cpd). This provides a unique possibility of a day by day study of variations of the neutron field in a deep underground site. The measured average 4$\pi$ neutron flux per cm$^{2}$ in the proximity of EDELWEISS-II is $\Phi_{MB}=3.57\pm0.05^{stat}\pm0.27^{syst}\times 10^{-6}$ neutrons/sec. We report the first experimental observation that the point-to-point thermal neutron flux at LSM varies by more than a factor two. Comment: submitted to Journal of Physics G: Nuclear and Particle Physics, 8 pages, 4 figures
01/2010;
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E. Armengaud,
C. Augier,
A. Benoit,
L. Berge,
O. Besida,
J. Blumer,
A. Broniatowski,
A. Chantelauze,
M. Chapellier,
G. Chardin, [......],
B. Paul,
S. Rozov,
V. Sanglard,
S. Scorza,
S. Semikh,
A. S. Torrento-Coello,
L. Vagneron,
M-A. Verdier,
E. Yakushev,
The EDELWEISS Collaboration
[show abstract]
[hide abstract]
ABSTRACT: The 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. Comment: 14 pages, 3 figures. Submitted to Phys Lett. B
12/2009;
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S. Marnieros,
E. Armengaud,
C. Augier,
L. Bergé,
A. Benoit,
O. Besida,
J. Blümer,
A. Broniatowski,
A. Chantelauze,
M. Chapellier, [......],
R. Lemrani,
A. Lubashevskiy,
C. Marrache,
Y. Ricci,
V. Sanglard,
S. Scorza,
S. Semikh,
M.-A. Verdier,
L. Vagneron,
E. Yakushev
[show abstract]
[hide abstract]
ABSTRACT: A new design for the Ge bolometers of the EDELWEISS project is described
here, based on innovative interleaved charge collection electrodes with
high background discrimination capabilities. The measured surface event
rejection is compatible with WIMP sensitivity levels down to
10-9 picobarn (pb). Use of interleaved electrodes on the
overall surface of the Ge crystal, including its lateral surface,
results to a high fiducial volume of the order of 80%. Electronic setup
is fairly simple with a total of five JFET based read-out amplifiers,
one for the NTD-Ge heat channel and four for the ionization signal.
Fabrication process is quite simple and the design is easily scalable to
higher mass bolometers (1 kg Ge crystal), making it very appealing for
the future 1 ton scale EUREKA Dark Matter experiment.
11/2009; 1185:635-638.
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A. Broniatowski,
X. Defay,
E. Armengaud,
L. Berge,
A. Benoit,
O. Besida,
J. Blumer,
A. Chantelauze,
M. Chapellier,
G. Chardin, [......],
E. Olivieri,
P. Pari,
B. Paul,
S. Rozov,
V. Sanglard,
S. Scorza,
S. Semikh,
M-A. Verdier,
L. Vagneron,
E. Yakushev
[show abstract]
[hide abstract]
ABSTRACT: A new design of a cryogenic germanium detector for dark matter search is
presented, taking advantage of the coplanar grid technique of event
localisation for improved background discrimination. Experiments performed with
prototype devices in the EDELWEISS II setup at the Modane underground facility
demonstrate the remarkably high efficiency of these devices for the rejection
of low-energy $\beta$, approaching 10$^5$ . This opens the road to investigate
the range beyond 10$^{-8}$ pb in the WIMP-nucleon collision cross-sections, as
proposed in the EURECA project of a one-ton cryogenic detector mass.
Physics Letters B 05/2009; 681:305–309. · 3.95 Impact Factor
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E. Armengau,
M Bauer,
I. Bavykina,
A. Benoit,
A. Bento,
J. Blumer,
L. Bornschein,
A. Broniatowski,
G. Burghart,
P. Camus, [......],
C. Isaila,
J. Jochum,
A. Juillard,
M. Kiefer,
M. Kimmerle,
H. Kluck,
V. V. Kobychev,
G. P. Kovtun,
V. Kozlov,
H. Kraus
[show abstract]
[hide abstract]
ABSTRACT: Workshop RPSCINT'2008 was organized in Kyiv (Ukraine) on 9th and 10th September 2008. The idea was to bring together physicists, chemists, crystal scintillator experts and manufacturers to discuss the requirements of low-count rate experiments, in particular the required radiopurity and scintillation properties; selection and screening of input materials; purification of materials; raw compound preparation; crystal growing, annealing and handling; test of crystals; search for and development of new scintillating materials. Some contributions to the RPSCINT 2008 workshop are presented in these proceedings.
04/2009;
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A. Benoit,
M. Chapellier,
G. Chardin,
L. Dumoulin,
K Eitel, J Gascon,
G. Gerbier,
C. Goldbach,
J. Jochum,
A de Lesquen,
G. Nollez,
F. Proebst,
W. Seidel
[show abstract]
[hide abstract]
ABSTRACT: The ZEPLIN collaboration has recently published its first result presenting a maximum sensitivity of $1.1 \times 10^{-6}$ picobarn for a WIMP mass of $\approx$ 60 GeV. The analysis is based on a discrimination method using the different time distribution of scintillation light generated in electron recoil and nuclear recoil interactions. We show that the methodology followed both for the calibration of the ZEPLIN-I detector response and for the estimation of the discrimination power is not reliable enough to claim any background discrimination at the present stage. The ZEPLIN-I sensitivity appears then to be in the order of 10$^{-3}$ picobarn, three orders of magnitude above the claimed 1.1 10$^{-6}$ picobarn.
01/2006;
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V. Sanglard,
A. Benoit,
L. Bergé,
J. Blümer,
A. Broniatowski,
B. Censier,
L. Chabert,
M. Chapellier,
G. Chardin,
P. Charvin, [......],
J. Mallet,
S. Marnieros,
L. Mosca,
X.-F. Navick,
G. Nollez,
P. Pari,
L. Schoeffel,
M. Stern,
L. Vagneron,
V. Villar
[show abstract]
[hide abstract]
ABSTRACT: The final results of the EDELWEISS-I dark matter search using cryogenic heat-and-ionization Ge detectors are presented. The final data sample corresponds to an increase by a factor 5 in exposure relative to the previously published results. A recoil energy threshold of 13 keV or better was achieved with three 320 g detectors working simultaneously over four months of stable operation. Limits on the spin-independent cross section for the scattering of a weakly interacting massive particle on a nucleon are derived from an accumulated fiducial exposure of 62 kg d.
Phys. Rev. D. 06/2005; 71(12).
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G. Gerbier,
A. Benoît,
L. Bergé,
A. Broniatowski,
L. Chabert,
B. Chambon,
B. Chardin,
M. Chapellier,
P. Charvin,
M. De Jésus, [......],
O. Martineau,
L. Mosca,
X. -F. Navick,
G. Nollez,
P. Pari,
C. Riccio,
V. Sanglard,
L. Schoeffel,
M. Stern,
L. Vagneron
[show abstract]
[hide abstract]
ABSTRACT: The latest results obtained by the EDELWEISS WIMP (weakly interacting massive particles) direct detection experiment using
three heat-and-ionization 320-g germanium bolometers are given. Presently the most sensitive WIMP direct detection experiment
for WIMP mass >30 GeV, EDELWEISSI is testing a first region of SUSY models compatible with accelerator constraints. The status
and main characteristics of EDELWEISS-II, involving in a first stage 28 germanium bolometers and able to accommodate up to
120 detectors, are briefly presented, together with neutron background estimates.
Physics of Atomic Nuclei 10/2004; 67(11):2027-2031. · 0.57 Impact Factor
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The EDELWEISS Collaboration,
O. Martineau,
A. Benoit,
L. Berge,
A. Broniatowski,
L. Chabert,
B. Chambon,
M. Chapellier,
G. Chardin,
P. Charvin, [......],
N. Mirabolfathi,
L. Mosca,
X. -F. Navick,
G. Nollez,
P. Pari,
C. Riccio,
V. Sanglard,
L. Schoeffel,
M. Stern,
L. Vagneron
[show abstract]
[hide abstract]
ABSTRACT: 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 A
10/2003;
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A. Benoit,
L. Berge,
A. Broniatowski,
L. Chabert,
B. Chambon,
M. Chapellier,
G. Chardin,
P. Charvin,
M. De Jesus,
P. Di Stefano, [......],
O. Martineau,
N. Mirabolfathi,
L. Mosca,
X. -F. Navick,
G. Nollez,
P. Pari,
C. Riccio,
V. Sanglard,
M. Stern,
L. Vagneron
[show abstract]
[hide abstract]
ABSTRACT: The EDELWEISS experiment has improved its sensitivity for the direct search for WIMP dark matter. In the recoil energy range relevant for WIMP masses below 10 TeV/c2, no nuclear recoils were observed in the fiducial volume of a heat-and-ionization cryogenic Ge detector operated in the low-background environment of the Laboratoire Souterrain de Modane in the Frejus Tunnel, during an effective exposure of 7.4 kg.days. This result is combined with the previous EDELWEISS data to derive a limit on the cross-section for spin-independent interaction of WIMPs and nucleons as a function of WIMP mass, using standard nuclear physics and astrophysical assumptions. This limit excludes at more than 99.8%CL a WIMP candidate with a mass of 44 GeV/c2 and a cross-section of 5.4 x 10-6 pb, as reported by the DAMA collaboration. A first sample of supersymmetric models are also excluded at 90%CL.
07/2002;
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[show abstract]
[hide abstract]
ABSTRACT: The EDELWEISS experiment used in 2001 a 320g heat-and-ionization cryogenic Ge detector operated in a low-background environment in the Laboratoire Souterrain de Modane for direct WIMP detection. This detector presents an increase of more than 4 times the mass of previous detectors. Calibrations of this detector are used to determine its energy resolution and fiducial volume, and to optimize the detector design for the 1kg phase of the EDELWEISS-I experiment. Analysis of the calibrations and characteristics of a first series of 320g-detectors are presented. Comment: 4 pages, 3 figures
05/2002;
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X.-F. Navick,
A. Benoit,
L. Bergé,
A. Broniatowski,
B. Chambon,
M. Chapellier,
G. Chardin,
P. Charvin,
M. De Jésus,
D. Drain, [......],
J. Mallet,
S. Marnieros,
O. Martineau,
N. Mirabolfathi,
L. Mosca,
G. Nollez,
P. Pari,
L. Schoeffel,
M. Stern,
L. Vagneron
[show abstract]
[hide abstract]
ABSTRACT: The EDELWEISS collaboration has performed a direct search for WIMPs using a 320g ionization-heat Ge-cryogenic detector operated in a low-background environment in the Laboratoire Souterrain de Modane. No nuclear recoils events are observed in the fiducial volume in the 30-200 keV energy range during an effective exposure of 4.53 kg.days. A limit on the cross-section of the WIMP-proton spin-independent interaction as a function of the WIMP mass is deduced. The central value of the signal reported by the DAMA experiment is excluded at 90% CL. © 2002 American Institute of Physics.
AIP Conference Proceedings. 02/2002; 605(1):489-492.
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A. Benoit,
L. Berge,
A. Broniatowski,
B. Chambon,
M. Chapellier,
G. Chardin,
P. Charvin,
M. De Jesus,
P. Di Stefano,
D. Drain, [......],
S. Marnieros,
O. Martineau,
N. Mirabolfathi,
L. Mosca,
L. Miramonti,
X. -F. Navick,
G. Nollez,
P. Pari,
M. Stern,
L. Vagneron
[show abstract]
[hide abstract]
ABSTRACT: The EDELWEISS collaboration has performed a direct search for WIMP dark matter using a 320 g heat-and-ionization cryogenic Ge detector operated in a low-background environment in the Laboratoire Souterrain de Modane. No nuclear recoils are observed in the fiducial volume in the 30-200 keV energy range during an effective exposure of 4.53 kg.days. Limits for the cross-section for the spin-independent interaction of WIMPs and nucleons are set in the framework of the Minimal Supersymmetric Standard Model (MSSM). The central value of the signal reported by the experiment DAMA is excluded at 90% CL. Comment: 14 pages, Latex, 4 figures. Submitted to Phys. Lett. B
06/2001;
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A. Juillard,
A. Benoit,
L. Berge,
A. Bonnevaux,
R. Bouvier,
A. Broniatowski,
B. Chambon,
M. Chapellier,
G. Chardin,
P. Charvin, [......],
O. Martineau,
N. Mirabolfathi,
L. Mosca,
X. -F. Navick,
G. Nollez,
P. Pari,
C. Pastor,
E. Simon,
M. Stern,
L. Vagneron
[show abstract]
[hide abstract]
ABSTRACT: The EDELWEISS Dark Matter Search uses low-temperature Ge detectors with heat and ionisation read-out to identify nuclear recoils induced by elastic collisions with WIMPs from the galactic halo. Preliminary results obtained with 320g bolometers are described. After a few weeks of data taking, data accumulated with one of these detectors already allow to reach the upper part of the DAMA region. Prospects for the present run and the second stage of the experiment, EDELWEISS-II, using an innovative reversed cryostat allowing data taking with 100 detectors, are briefly described.
05/2001;
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J Gascon,
A. Benoit,
A. Bonnevaux,
L. Berge,
A. Broniatowski,
B. Chambon,
M. Chapellier,
G. Chardin,
P. Charvin,
P. Cluzel, [......],
L. Miramonti,
L. Mosca,
X. -F. Navick,
G. Nollez,
P. Pari,
C. Pastor,
E. Simon,
M. Stern,
L. Vagneron,
Jules Gascon
[show abstract]
[hide abstract]
ABSTRACT: The EDELWEISS Dark Matter search uses low-temperature Ge detectors with heat and ionisation read- out to identify nuclear recoils induced by elastic collisions with WIMPs from the galactic halo. Results from the operation of 70 g and 320 g Ge detectors in the low-background environment of the Modane Underground Laboratory (LSM) are presented.
02/2001;
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M. Chapellier,
A. Benoit,
L. Berge,
A. Broniatowski,
B. Chambon,
G. Chardin,
P. Charvin,
M. De Jesus,
P. Di Stefano,
D. Drain, [......],
N. Mirabolfathi,
L. Miramonti,
L. Mosca,
X. -F. Navick,
G. Nollez,
P. Pari,
C. Pastor,
E. Simon,
M. Stern,
L. Vagneron
[show abstract]
[hide abstract]
ABSTRACT: Preliminary results obtained with 320g bolometers with simultaneous ionization and heat measurements are described. After a few weeks of data taking, data accumulated with one of these detectors are beginning to exclude the upper part of the DAMA region. Prospects for the present run and the second stage of the experiment, EDELWEISS-II, using an innovative reversed cryostat allowing data taking with 100 detectors, are briefly described.
02/2001;
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S. Fiorucci,
Alain Benoit,
L. Berge,
J. Blumer,
A. Broniatowski,
B. Censier,
A. Chantelauze,
M. Chapellier,
G. Chardin,
S. Collin, [......],
L. Mosca,
X. -F. Navick,
G. Nollez,
O. Olivieri,
P. Pari,
V. Sanglard,
L. Schoeffel,
F. Schwamm,
M. Stern,
E. Yakushev
[show abstract]
[hide abstract]
ABSTRACT: This paper presents our interpretation and understanding of the different backgrounds in the EDELWEISS-I data sets. We analyze in detail the several populations observed, which include gammas, alphas, neutrons, thermal sensor events and surface events, and try to combine all data sets to provide a coherent picture of the nature and localisation of the background sources. In light of this interpretation, we draw conclusions regarding the background suppression scheme for the EDELWEISS-II phase.
