84 research outputs found
Radiogenic and Muon-Induced Backgrounds in the LUX Dark Matter Detector
The Large Underground Xenon (LUX) dark matter experiment aims to detect rare
low-energy interactions from Weakly Interacting Massive Particles (WIMPs). The
radiogenic backgrounds in the LUX detector have been measured and compared with
Monte Carlo simulation. Measurements of LUX high-energy data have provided
direct constraints on all background sources contributing to the background
model. The expected background rate from the background model for the 85.3 day
WIMP search run is
~events~keV~kg~day
in a 118~kg fiducial volume. The observed background rate is
~events~keV~kg~day,
consistent with model projections. The expectation for the radiogenic
background in a subsequent one-year run is presented.Comment: 18 pages, 12 figures / 17 images, submitted to Astropart. Phy
First Results from the LUX Dark Matter Experiment at the Sanford Underground Research Facility
The Large Underground Xenon (LUX) experiment is a dual-phase xenon time-projection chamber
operating at the Sanford Underground Research Facility (Lead, South Dakota). The LUX cryostat
was filled for the first time in the underground laboratory in February 2013. We report results of the first
WIMP search data set, taken during the period from April to August 2013, presenting the analysis of
85.3 live days of data with a fiducial volume of 118 kg. A profile-likelihood analysis technique shows our
data to be consistent with the background-only hypothesis, allowing 90% confidence limits to be set on
spin-independent WIMP-nucleon elastic scattering with a minimum upper limit on the cross section of
7.6 × 10−46 cm2 at a WIMP mass of 33 GeV=c2. We find that the LUX data are in disagreement with lowmass
WIMP signal interpretations of the results from several recent direct detection experiments
First Results from the LUX Dark Matter Experiment at the Sanford Underground Research Facility
The Large Underground Xenon (LUX) experiment, a dual-phase xenon
time-projection chamber operating at the Sanford Underground Research Facility
(Lead, South Dakota), was cooled and filled in February 2013. We report results
of the first WIMP search dataset, taken during the period April to August 2013,
presenting the analysis of 85.3 live-days of data with a fiducial volume of 118
kg. A profile-likelihood analysis technique shows our data to be consistent
with the background-only hypothesis, allowing 90% confidence limits to be set
on spin-independent WIMP-nucleon elastic scattering with a minimum upper limit
on the cross section of cm at a WIMP mass of 33
GeV/c. We find that the LUX data are in strong disagreement with low-mass
WIMP signal interpretations of the results from several recent direct detection
experiments.Comment: Accepted by Phys. Rev. Lett. Appendix A included as supplementary
material with PRL articl
Radiogenic and muon-induced backgrounds in the LUX dark matter detector
The Large Underground Xenon (LUX) dark matter experiment aims to detect rare low-energy interactions from Weakly Interacting Massive Particles (WIMPs). The radiogenic backgrounds in the LUX detector have been measured and compared with Monte Carlo simulation. Measurements of LUX high-energy data have provided direct constraints on all background sources contributing to the background model. The expected background rate from the background model for the 85.3 day WIMP search run is
(2.6±0.2stat±0.4sys)×10-3
events
keVee-1kg-1day-1
in a 118 kg fiducial volume. The observed background rate is
(3.6±0.4stat)×10-3
events
keVee-1kg-1day-1
, consistent with model projections. The expectation for the radiogenic background in a subsequent one-year run is presented
Improved Limits on Scattering of Weakly Interacting Massive Particles from Reanalysis of 2013 LUX Data
We present constraints on weakly interacting massive particles (WIMP)-nucleus scattering from the 2013 data of the Large Underground Xenon dark matter experiment, including 1.4×104 kg day of search exposure. This new analysis incorporates several advances: single-photon calibration at the scintillation wavelength, improved event-reconstruction algorithms, a revised background model including events originating on the detector walls in an enlarged fiducial volume, and new calibrations from decays of an injected tritium β source and from kinematically constrained nuclear recoils down to 1.1 keV. Sensitivity, especially to low-mass WIMPs, is enhanced compared to our previous results which modeled the signal only above a 3 keV minimum energy. Under standard dark matter halo assumptions and in the mass range above 4 GeV c-2, these new results give the most stringent direct limits on the spin-independent WIMP-nucleon cross section. The 90% C.L. upper limit has a minimum of 0.6 zb at 33 GeV c-2 WIMP mass
First Results from the LUX Dark Matter Experiment at the Sanford Underground Research Facility
The Large Underground Xenon (LUX) experiment, a dual-phase xenon
time-projection chamber operating at the Sanford Underground Research Facility
(Lead, South Dakota), was cooled and filled in February 2013. We report results
of the first WIMP search dataset, taken during the period April to August 2013,
presenting the analysis of 85.3 live-days of data with a fiducial volume of 118
kg. A profile-likelihood analysis technique shows our data to be consistent
with the background-only hypothesis, allowing 90% confidence limits to be set
on spin-independent WIMP-nucleon elastic scattering with a minimum upper limit
on the cross section of cm at a WIMP mass of 33
GeV/c. We find that the LUX data are in strong disagreement with low-mass
WIMP signal interpretations of the results from several recent direct detection
experiments.Comment: Accepted by Phys. Rev. Lett. Appendix A included as supplementary
material with PRL articl
Results on the Spin-Dependent Scattering of Weakly Interacting Massive Particles on Nucleons from the Run 3 Data of the LUX Experiment
We present experimental constraints on the spin-dependent WIMP (weakly interacting massive particle)-nucleon elastic cross sections from LUX data acquired in 2013. LUX is a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility (Lead, South Dakota), which is designed to observe the recoil signature of galactic WIMPs scattering from xenon nuclei. A profile likelihood ratio analysis of 1.4×104 kg day of fiducial exposure allows 90% C.L. upper limits to be set on the WIMP-neutron (WIMP-proton) cross section of σn=9.4×10-41 cm2 (σp=2.9×10-39 cm2) at 33 GeV/c2. The spin-dependent WIMP-neutron limit is the most sensitive constraint to date
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