2,590,023 research outputs found
137Cs measurement uncertainties and detection limits for airborne gamma spectrometry (AGS) data analysed using a spectral windows method
The uncertainties associated with airborne gamma spectrometry (AGS) measurements analysed using a spectral windows method, and associated detection limits, have been investigated. For individual short measurements over buried 137Cs activity detection limits of are achieved. These detection limits are reduced for superficial activity and longer integration times. For superficial activity, detection limits below are achievable. A comparison is made with the detection limits for other data processing methods
Limits on dark matter proton scattering from neutrino telescopes using micrOMEGAs
Limits on dark matter spin dependent elastic scattering cross section on
protons derived from IceCube data are obtained for different dark matter
annihilation channels using micrOMEGAs. The uncertainty on the derived limits,
estimated by using different neutrino spectra, can reach a factor two. For all
dark matter annihilation channels except for quarks, the limits on the spin
dependent cross section are more stringent than those obtained in direct
detection experiments. The new functions that allow to derive those limits are
described.Comment: 23 pages, 7 figures; v2: references added; v3 and v4: clarifications
added; The code can be downloaded from https://lapth.cnrs.fr/micromega
The HI Content of Compact Groups of Galaxies
The HI content of Hickson Compact Groups in the southern hemisphere is
measured using data from the HI Parkes All Sky Survey (HIPASS), and dedicated
observations using the narrowband filter on the Multibeam instrument on the
Parkes telescope. The expected HI mass of these groups was estimated using the
luminosity, diameter and morphological types of the member galaxies, calibrated
from published data. Taking careful account of non-detection limits, the
results show that the compact group population that has been detected by these
observations has an HI content similar to that of galaxies in the reference
field sample. The upper limits for the undetected groups lie within the normal
range; improvement of these limits will require a large increase in
sensitivity.Comment: 27 pages, 5 figures. Accepted for publication in PAS
Interpreting the bounds on Solar Dark Matter induced muons at Super-Kamiokande in the light of CDMS results
We consider the recent limits on dark matter - nucleon elastic scattering
cross section from the analysis of CDMS II collaboration using the two signal
events observed in CDMS experiment. With these limits we try to interpret the
Super-Kamiokande (SK) bounds on the detection rates of up-going muons induced
by the neutrinos that are produced in the sun from the decay of annihilation
products of dark matter (WIMPs) captured in the solar core. Calculated rates of
up-going muons for different annihilation channels at SK using CDMS bounds are
found to be orders below the predicted upper limits of such up-going muon rates
at SK. Thus there exists room for enhancement (boost) of the calculated rates
using CDMS limits for interpreting SK bounds. Such a feature is expected to
represent the PAMELA data with the current CDMS limits. We also show the
dependence of such a possible enhancement factor (boost) on WIMP mass for
different WIMP annihilation channels.Comment: 7 pages, 6 figure
Extending the CRESST-II commissioning run limits to lower masses
Motivated by the recent interest in light WIMPs of mass ~O(10 GeV), an
extension of the elastic, spin-independent WIMP-nucleon cross-section limits
resulting from the CRESST-II commissioning run (2007) are presented.
Previously, these data were used to set cross-section limits from 1000 GeV down
to ~17 GeV, using tungsten recoils, in 47.9 kg-days of exposure of calcium
tungstate. Here, the overlap of the oxygen and calcium bands with the
acceptance region of the commissioning run data set is reconstructed using
previously published quenching factors. The resulting elastic WIMP cross
section limits, accounting for the additional exposure of oxygen and calcium,
are presented down to 5 GeV.Comment: 4 pages, 4 figure
Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV
A search for new physics is presented based on an event signature of at least
three jets accompanied by large missing transverse momentum, using a data
sample corresponding to an integrated luminosity of 36 inverse picobarns
collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector
at the LHC. No excess of events is observed above the expected standard model
backgrounds, which are all estimated from the data. Exclusion limits are
presented for the constrained minimal supersymmetric extension of the standard
model. Cross section limits are also presented using simplified models with new
particles decaying to an undetected particle and one or two jets
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