XMASS, a low-background, large liquid-xenon detector, was used to search for solar axions that would be produced by bremsstrahlung and Compton effects in the Sun. With an exposure of 5.6 ton days of ...liquid xenon, the model-independent limit on the coupling for mass ≪1 keV is |gaee|<5.4×10−11 (90% C.L.), which is a factor of two stronger than the existing experimental limit. The bounds on the axion masses for the DFSZ and KSVZ axion models are 1.9 and 250 eV, respectively. In the mass range of 10–40 keV, this study produced the most stringent limit, which is better than that previously derived from astrophysical arguments regarding the Sun to date.
Bosonic superweakly interacting massive particles (super-WIMPs) are a candidate for warm dark matter. With the absorption of such a boson by a xenon atom, these dark matter candidates would deposit ...an energy equivalent to their rest mass in the detector. This is the first direct detection experiment exploring the vector super-WIMPs in the mass range between 40 and 120 keV. With the use of 165.9 day of data, no significant excess above background was observed in the fiducial mass of 41 kg. The present limit for the vector super-WIMPs excludes the possibility that such particles constitute all of dark matter. The absence of a signal also provides the most stringent direct constraint on the coupling constant of pseudoscalar super-WIMPs to electrons. The unprecedented sensitivity was achieved exploiting the low background at a level 10(-4) kg-1 keVee-1 day-1 in the detector.
A search for light dark matter using low-threshold data from the single phase liquid xenon scintillation detector XMASS, has been conducted. Using the entire 835 kg inner volume as target, the ...analysis threshold can be lowered to 0.3 keVee (electron-equivalent) to search for light dark matter. With low-threshold data corresponding to a 5591.4 kg day exposure of the detector and without discriminating between nuclear-recoil and electronic events, XMASS excludes part of the parameter space favored by other experiments.
Radon removal from gaseous xenon with activated charcoal Abe, K.; Hieda, K.; Hiraide, K. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2012, 2012-01-00, 20120101, Volume:
661, Issue:
1
Journal Article
Peer reviewed
Many low background experiments using xenon need to remove radioactive radon to improve their sensitivities. However, no method of continually removing radon from xenon has been described in the ...literature. We studied a method to remove radon from xenon gas through an activated charcoal trap. From our measurements we infer a linear relationship between the mean propagation velocity
v
Rn
of radon and
v
Xe
of xenon in the trap with
v
Rn
/
v
Xe
=
(
0.96
±
0.10
)
×
10
−
3
at −85
°C. As the mechanism for radon removal in this charcoal trap is its decay, knowledge of this parameter allows us to design an efficient radon removal system for the XMASS experiment. The verification of this system found that it reduces radon by a factor of 0.07, which is in line with its expected average retention time of 14.8 days for radon.
XMASS detector Abe, K.; Hieda, K.; Hiraide, K. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2013, Volume:
716
Journal Article
Peer reviewed
Open access
The XMASS project aims to detect dark matter, pp and 7Be solar neutrinos, and neutrinoless double beta decay using ultra pure liquid xenon. The first phase of the XMASS experiment searches for dark ...matter. In this paper, we describe the XMASS detector in detail, including its configuration, data acquisition equipment and calibration system.
A search for inelastic scattering of weakly interacting massive particles (WIMPs) on the isotope
$^{129}$
Xe was done in data taken with the single-phase liquid-xenon detector XMASS at the Kamioka ...Observatory. Using a restricted volume containing 41 kg of liquid xenon at the very center of our detector, we observed no significant excess of events in 165.9 live days of data. Our background reduction allowed us to derive our limits without explicitly subtracting the remaining events that are compatible with background expectations. As an example, we derive for a 50 GeV WIMP an upper limit of 3.2 pb at the 90% confidence level for its inelastic cross section on
$^{129}$
Xe nuclei.
Micro-source development for XMASS experiment Kim, N.Y.; Abe, K.; Hieda, K. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2015, Volume:
784
Journal Article
Peer reviewed
XMASS is a multipurpose liquid-xenon detector that currently aims to directly detect dark matter. In this paper, we describe the fabrication and characterization of reference sources used for the ...energy calibration and position reconstruction of the present XMASS detector. Several gamma-ray sources were produced in the form of a sealed needle-source. A thin-wall tube with a diameter of approximately 0.2mm was sealed at both ends, with the 241Am or 57Co source material contained inside. The active region of the source was observed to be 1–2mm long, close to the tip of the needle. These sources were tested in the XMASS detector, and the results were compared with Monte-Carlo simulations.
Bosonic superweakly interacting massive particles (super-WIMPs) are a candidate for warm dark matter. With the absorption of such a boson by a xenon atom these dark matter candidates would deposit an ...energy equivalent to their rest mass in the detector. This is the first direct detection experiment exploring the vector super-WIMPs in the mass range between 40 and 120 keV. Using 165.9 days of data no significant excess above background was observed in the fiducial mass of 41 kg. The present limit for the vector super-WIMPs excludes the possibility that such particles constitute all of dark matter. The absence of a signal also provides the most stringent direct constraint on the coupling constant of pseudoscalar super-WIMPs to electrons. The unprecedented sensitivity was achieved exploiting the low background at a level \(10^{-4}\) kg\(^{-1}\)keV\(_{ee}^{-1}\)day\(^{-1}\) in the detector.
A search for inelastic scattering of Weakly Interacting Massive Particles (WIMPs) on the isotope \(^{129}\)Xe was done in data taken with the single phase liquid xenon detector XMASS at the Kamioka ...Observatory. Using a restricted volume containing 41 kg of LXe at the very center of our detector we observed no significant excess of events in 165.9 days of data. Our background reduction allowed us to derive our limits without explicitly subtracting the remaining events which are compatible with background expectations and derive for e.g. a 50 GeV WIMP an upper limit for its inelastic cross section on \(^{129}\)Xe nuclei of 3.2 pb at the 90% confidence level.
XMASS, a low-background, large liquid-xenon detector, was used to search for solar axions that would be produced by bremsstrahlung and Compton effects in the Sun. With an exposure of 5.6ton days of ...liquid xenon, the model-independent limit on the coupling for mass \(\ll\) 1keV is \(|g_{aee}|< 5.4\times 10^{-11}\) (90% C.L.), which is a factor of two stronger than the existing experimental limit. The bounds on the axion masses for the DFSZ and KSVZ axion models are 1.9 and 250eV, respectively. In the mass range of 10-40keV, this study produced the most stringent limit, which is better than that previously derived from astrophysical arguments regarding the Sun to date.
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