共查询到20条相似文献,搜索用时 15 毫秒
1.
S. V. Rozov V. B. Brudanin A. V. Lubashevskiy S. S. Semikh D. V. Filosofov E. A. Yakushev on behalf of EDELWEISS Collaboration 《Bulletin of the Russian Academy of Sciences: Physics》2010,74(4):464-466
The results from measurements of thermal neutron flux in the EDELWEISS II experiment aimed at the direct detection of WIMPs
(weakly interacting massive particles) by means of cryogenic germanium bolometers are described. Detailed knowledge of the
neutron background is of crucial importance for the experiment, since neutrons with the MeV energy range of scattering seem
to be hard to distinguish from the expected WIMP signal within the bolometers. Monitoring of the thermal neutron flux is performed
using a mobile detection system with a low background proportional 3He counter. The neutron flux measurements were performed both outside and inside the device’s shielding, in the direct proximity
of a cryostat with built-in germanium detectors. The sensitivity of the created thermal neutron detection system is on the
level of 10−9 neutron (cm2 s)−1. 相似文献
2.
The EDELWEISS experiment is aimed at direct searches for nonbaryonic cold dark matter by means of cryogenic germanium detectors. It is deployed at the LSM underground laboratory in the Frejus tunnel, which connects France and Italy. The results of the experimentmade it possible to set a limit on the spin-independent cross section for the scattering of weak-interacting massive particles (WIMP) at a level of 10?6 pb. Data from 21 detectors of total mass about 7 kg are being accumulated at the present time. 相似文献
3.
Ahmed Z Akerib DS Arrenberg S Bailey CN Balakishiyeva D Baudis L Bauer DA Brink PL Bruch T Bunker R Cabrera B Caldwell DO Cooley J do Couto e Silva E Cushman P Daal M DeJongh F Di Stefano P Dragowsky MR Duong L Fallows S Figueroa-Feliciano E Filippini J Fox J Fritts M Golwala SR Hall J Hennings-Yeomans R Hertel SA Holmgren D Hsu L Huber ME Kamaev O Kiveni M Kos M Leman SW Liu S Mahapatra R Mandic V McCarthy KA Mirabolfathi N Moore D Nelson H Ogburn RW Phipps A Pyle M Qiu X Ramberg E Rau W 《Physical review letters》2011,106(13):131302
We report results from a reanalysis of data from the Cryogenic Dark Matter Search (CDMS II) experiment at the Soudan Underground Laboratory. Data taken between October 2006 and September 2008 using eight germanium detectors are reanalyzed with a lowered, 2 keV recoil-energy threshold, to give increased sensitivity to interactions from weakly interacting massive particles (WIMPs) with masses below ~10 GeV/c(2). This analysis provides stronger constraints than previous CDMS II results for WIMP masses below 9 GeV/c(2) and excludes parameter space associated with possible low-mass WIMP signals from the DAMA/LIBRA and CoGeNT experiments. 相似文献
4.
Weakly interacting massive particle (WIMP) is well known to be a good candidate for dark matter, and it is also predicted by many new physics models beyond the standard model at the TeV scale. We found that, if the WIMP is a vector particle (spin-one particle) which is associated with some gauge symmetry broken at the TeV scale, the Higgs mass is often predicted to be 120–125 GeV, which is very consistent with the result of Higgs searches recently reported by ATLAS and CMS Collaborations at the Large Hadron Collider experiment. In this Letter, we consider the vector WIMP using a non-linear sigma model in order to confirm this result as general as possible in a bottom-up approach. Near-future prospects to detect the vector WIMP at both direct and indirect detection experiments of dark matter are also discussed. 相似文献
5.
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 73Ge 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. 相似文献
6.
C. Bobin N. Coron G. Dambier E. García C. Goldbach D. Gonzlez J. Leblanc P. de Marcillac A. Morales J. Morales G. Nollez A. Ortiz de Solrzano J. Puimedn A. Salinas M. L. Sarsa S. Scopel J. A. Villar 《Nuclear Physics B - Proceedings Supplements》1999,70(1-3)
An experiment to look for light WIMPs with sapphire bolometers is to be installed in the Canfranc Underground Laboratory (at 2450 m.w.e) in the Spanish Pyrenees. In the first stage two small 25g bolometers with NTD-Ge sensors, operating at 25mK, with an energy threshold of 300eV and FWHM energy resolution of 120eV at 1.5keV will perform a background test experiment. The features of the bolometers, the radioactivity measurements of the components and the set-up and status of the experiment are reported. 相似文献
7.
《Physics letters. [Part B]》2011,702(5):329-335
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 γ-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 4.4×10−8 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. 相似文献
8.
E. A. Yakushev V. B. Brudanin A. V. Lubashevskii S. V. Rozov S. S. Semikh D. V. Filosofov 《Russian Physics Journal》2010,53(6):611-615
The EDELWEISS-II experiment is aimed at direct detection of weakly interacting massive particles (WIMP) considered as main
candidates for the role of nonbarion dark matter. In the experiment, a search for rare WIMP-Ge scattering events is performed
using HPGe-detectors-bolometers at a temperature of 20 mK. Because of different ionization losses of recoil nuclei and electrons,
the use of detectors allowing simultaneous measurement of phonon and ionization signals enables background events to be suppressed
very efficiently. To suppress actively the remained source of events simulating the WIMP signature, namely, the surface events
with incomplete charge collection, detectors with coplanar ring electrodes have been developed for the EDELWEISS-II facility.
The experimental coefficient of suppression of all EDELWEISS-II background components with the help of calibration measurements
allows 3500 kg⋅day statistics to be accumulated with the expected zero level of the background events in the region of search
for the WIMP. This enables the spinindependent WIMP-nucleon scattering events to be registered given that their cross section
is greater than 10-45 cm2 (10-9 pb) predicted by a wide class of the SUSY models. 相似文献
9.
10.
Xiangpan Ji Ye Xu Junsong Lin Yulong Feng Haolin Li 《Journal of Experimental and Theoretical Physics》2013,117(5):792-799
A direct WIMP (weakly interacting massive particle) detector with a neutron veto system is designed to better reject neutrons. The experimental configuration is studied in this paper involves 984 Ge modules placed inside a reactor-neutrino detector. The neutrino detector is used as a neutron veto device. The neutron background for the experimental design is estimated using the Geant4 simulation. The results show that the neutron background can decrease to O(0.01) events per year per tonne of high-purity germanium and it can be ignored in comparison with electron recoils. 相似文献
11.
W. Seidel M. Bravin M. Bruckmayer C. Bucci S. Cooper P. DiStefano F. V. Feilitzsch T. Frank J. Jochum R. Keeling H. Kraus M. Loidl J. Marchese O. Meier P. Meunier U. Nagel D. Pergolesi F. Pröbst Y. Ramachers J. Schnagl I. Sergeyev M. Sisti L. Stodolsky S. Uchaikin L. Zerle 《Physics of Atomic Nuclei》2000,63(7):1242-1248
We discuss the short-and long-term perspectives of the CRESST (Cryogenic Rare Event Search using Superconducting Thermometers) project and present the current status of the experiment and new results concerning detector development. In the search for elementary particle dark matter, CRESST is presently the most advanced deep underground, low-background, cryogenic facility. The basic technique involved is to search for WIMPs (Weakly Interacting Massive Particles) by the measurement of nonthermal phonons, as created by WIMP-induced nuclear recoils. Combined with our newly developed method for the simultaneous measurement of scintillation light, strong background discrimination is possible, resulting in a substantial increase in WIMP detection sensitivity. This will allow a test of the reported positive evidence for a WIMP signal by the DAMA Collaboration in the near future. In the long term, the present CRESST setup permits the installation of a detector mass up to 100 kg. In contrast to other projects, CRESST technology allows the employment of a large variety of detection materials. This offers a powerful tool in establishing a WIMP signal and in investigating WIMP properties in the event of a positive signal. 相似文献
12.
V. A. Bednyakov 《Physics of Particles and Nuclei》2007,38(3):326-363
Weakly interacting massive particles (WIMPs) are among the main candidates for the relic dark matter (DM). The idea of direct
DM detection relies on elastic spin-dependent (SD) and spin-independent (SI) interaction of WIMPs with target nuclei. In this
review, formulas for the DM event rate calculations are collected. The importance of the SD WIMP-nucleus interaction for reliable
DM detection is argued and the spin nuclear structure functions relevant to DM search are discussed. The effective low-energy
minimal supersymmetric standard model (MSSM) is used for calculation of the DM cross sections, provided the lightest neutralino
is the WIMP. It is shown that the absolute lower bound for the rate of direct DM detection is due to the SD WIMP-nucleon interaction
and a new-generation experiment aimed at detecting DM with sensitivity higher than 10−5 event/day/kg should have a non-zero-spin target to avoid missing of the DM signal. The mixed spin-scalar couplings approach
is argued. Prospects of DM experiments with high-spin Ge-73 are discussed in the mixed coupling scheme. The DAMA experiment
has claimed observation of WIMPs due to annual signal modulation. Some important consequences of the DAMA claim for the other
DM searches as well as for collider physics are considered.
The text was submitted by the author in English. 相似文献
13.
JingLu Ma Qian Yue ShinTed Lin Henry Tsz-King Wong JinWei Hu LiPing Jia Hao Jiang Jin Li ShuKui Liu ZhongZhi Liu Hao Ma WeiYou Tang Yang Tian Li Wang Qing Wang Yi Wang LiTao Yang Zhi Zeng 《中国科学:物理学 力学 天文学(英文版)》2019,(1)
A study on cosmogenic activation in germanium was carried out to evaluate the cosmogenic background level of natural and ~(70)Ge depleted germanium detectors. The production rates of long-lived radionuclides were calculated with Geant4 and CRY.Results were validated by comparing the simulated and experimental spectra of CDEX-1B detector. Based on the validated codes, the cosmogenic background level was predicted for further tonne-scale CDEX experiment. The suppression of cosmogenic background level could be achieved by underground germanium crystal growth and high-purity germanium detector fabrication to reach the sensitivity requirement for direct detection of dark matter. With the low cosmogenic background, new physics channels,such as solar neutrino research and neutrinoless double-beta decay experiments, were opened and the corresponding simulations and evaluations were carried out. 相似文献
14.
J.D.Vergados 《理论物理通讯》2012,57(3):504-514
The differential event rate for direct detection of dark matter,both the time averaged and the modulated one due to the motion of the Earth,are discussed.The calculations focus on relatively light cold dark matter candidates (WIMP) and low energy transfers.It is shown that for sufficiently light WIMPs the extraction of relatively large nucleon cross sections is possible.Furthermore for some WIMP masses the modulation amplitude may change sign,meaning that,in such a case,the maximum rate may occur six months later than naively expected.This effect can be exploited to yield information about the mass of the dark matter candidate,if and when the observation of the modulation of the event rate is established. 相似文献
15.
The signals observed at the direct detection experiments DAMA, CoGeNT and CRESST could be explained by light WIMPs with sizeable spin-independent cross sections with nucleons. The capture and subsequent annihilation of such particles in the Sun would induce neutrino signals in the GeV range which may be observed at Super-Kamiokande. We determine the rate of upward stopping muons and fully contained events at Super-Kamiokande for various possible WIMP annihilation channels. This allows us to provide strong constraints on the cross section of WIMPs with nucleons. We find that the DAMA and CoGeNT signals are inconsistent with standard thermal WIMPs annihilating dominantly into neutrino or tau pairs. We also provide limits for spin-dependent WIMP nucleus scattering for masses up to 80 GeV. These exclude the DAMA favored region if WIMPs annihilate even subdominantly into neutrinos, taus, bottoms or charms. 相似文献
16.
暗物质研究是21世纪粒子物理、天体物理和宇宙学最重要的前沿科学课题之一.暗物质被天文学中的引力效应所观察到,但对它的存在和认识仍旧是个谜.文章主要论述了对弱作用大质量暗物质粒子(WIMP)直接探测的基本原理、各种直接探测技术、当前的实验进展和发展方向.最后给出了最近的实验物理结果. 相似文献
17.
J. Conrad J. Cohen-Tanugi L. E. Strigari 《Journal of Experimental and Theoretical Physics》2015,121(6):1104-1135
The launch of the gamma-ray telescope Fermi Large Area Telescope (Fermi-LAT) started a pivotal period in indirect detection of dark matter. By outperforming expectations, for the first time a robust and stringent test of the paradigm of weakly interacting massive particles (WIMPs) is within reach. In this paper, we discuss astrophysical targets for WIMP detection and the challenges they present, review the analysis tools which have been employed to tackle these challenges, and summarize the status of constraints on and the claimed detections in the WIMP parameter space. Methods and results will be discussed in comparison to Imaging Air Cherenkov Telescopes. We also provide an outlook on short term and longer term developments. 相似文献
18.
Rudolf Novák 《Czechoslovak Journal of Physics》1958,8(2):196-207
A theory of metallic bolometers is given for the case that the measured radiation is periodically interrupted. The impedance of a bolometer through which a direct and an alternating current simultaneously flow, is derived generally. Separate solutions are given for bolometers cooled by heat conduction and bolometers with thermal impedance dependent on the temperature. Expressions are derived for the sensitivity and minimum measurable power and the conditions for the choice of a coupling transformer with optimum ratio. In conclusion the lowest value of the minimum power at all measurable by metallic bolometers working in interrupted radiation is determined.Delivered in an abbreviated form. at the congress of the Physics Society of the German Democratic Republic in Leipzig, April 11, 1957. 相似文献
19.
A weakly interacting massive particle (WIMP) is perhaps the most promising candidate for the dark matter in the Galactic halo. The WIMP detection rate in laboratory searches is fixed by the cross section for elastic WIMP-nucleus scattering. Here we calculate the contribution to this cross section from two-nucleon currents from pion exchange in the nucleus and show that it may, in some cases, be comparable to the one-nucleon current that has been considered in prior work and perhaps help resolve the discrepancies between the various direct dark-matter search experiments. We provide simple expressions that allow these new contributions to be included in current calculations. 相似文献
20.
Akerib DS Alvaro-Dean J Armel-Funkhouser MS Attisha MJ Baudis L Bauer DA Beaty J Brink PL Bunker R Burke SP Cabrera B Caldwell DO Callahan D Castle JP Chang CL Choate R Crisler MB Cushman P Dixon R Dragowsky MR Driscoll DD Duong L Emes J Ferril R Filippini J Gaitskell RJ Haldeman M Hale D Holmgren D Huber ME Johnson B Johnson W Kamat S Kozlovsky M Kula L Kyre S Lambin B Lu A Mahapatra R Manalaysay AG Mandic V May J McDonald R Merkel B Meunier P Mirabolfathi N Morrison S Nelson H Nelson R 《Physical review letters》2004,93(21):211301
We report the first results from a search for weakly interacting massive particles (WIMPs) in the Cryogenic Dark Matter Search experiment at the Soudan Underground Laboratory. Four Ge and two Si detectors were operated for 52.6 live days, providing 19.4 kg d of Ge net exposure after cuts for recoil energies between 10 and 100 keV. A blind analysis was performed using only calibration data to define the energy threshold and selection criteria for nuclear-recoil candidates. Using the standard dark-matter halo and nuclear-physics WIMP model, these data set the world's lowest exclusion limits on the coherent WIMP-nucleon scalar cross section for all WIMP masses above 15 GeV/c2, ruling out a significant range of neutralino supersymmetric models. The minimum of this limit curve at the 90% C.L. is 4 x 10(-43) cm2 at a WIMP mass of 60 GeV/c2. 相似文献