441 research outputs found
Systematic study of trace radioactive impurities in candidate construction materials for EXO-200
The Enriched Xenon Observatory (EXO) will search for double beta decays of
136Xe. We report the results of a systematic study of trace concentrations of
radioactive impurities in a wide range of raw materials and finished parts
considered for use in the construction of EXO-200, the first stage of the EXO
experimental program. Analysis techniques employed, and described here, include
direct gamma counting, alpha counting, neutron activation analysis, and
high-sensitivity mass spectrometry.Comment: 32 pages, 6 figures. Expanded introduction, added missing table
entry. Accepted for publication in Nucl. Instrum. Meth.
Light Sterile Neutrinos: A White Paper
This white paper addresses the hypothesis of light sterile neutrinos based on
recent anomalies observed in neutrino experiments and the latest astrophysical
data
Indication for the disappearance of reactor electron antineutrinos in the Double Chooz experiment
The Double Chooz Experiment presents an indication of reactor electron
antineutrino disappearance consistent with neutrino oscillations. A ratio of
0.944 0.016 (stat) 0.040 (syst) observed to predicted events was
obtained in 101 days of running at the Chooz Nuclear Power Plant in France,
with two 4.25 GW reactors. The results were obtained from a single 10
m fiducial volume detector located 1050 m from the two reactor cores. The
reactor antineutrino flux prediction used the Bugey4 measurement as an anchor
point. The deficit can be interpreted as an indication of a non-zero value of
the still unmeasured neutrino mixing parameter \sang. Analyzing both the rate
of the prompt positrons and their energy spectrum we find \sang = 0.086
0.041 (stat) 0.030 (syst), or, at 90% CL, 0.015 \sang 0.16.Comment: 7 pages, 4 figures, (new version after PRL referee's comments
Precision Measurement of Neutrino Oscillation Parameters with KamLAND
The KamLAND experiment has determined a precise value for the neutrino
oscillation parameter and stringent constraints on
. The exposure to nuclear reactor anti-neutrinos is increased
almost fourfold over previous results to 2.44 proton-yr due to
longer livetime and an enlarged fiducial volume. An undistorted reactor
energy spectrum is now rejected at >5. Extending the
analysis down to the inverse beta decay energy threshold, and incorporating
geo-neutrinos, gives a best-fit at =
eV and
=. Local
-minima at higher and lower are disfavored
at >4. Combining with solar neutrino data, we obtain = eV and =.Comment: Version as published in PRL. Revised Fig. 2 (allowed contours) due to
an error in the figure generating code (numbers or conclusions did not
change). The full dChi2-map for this analysis is available at
http://www.awa.tohoku.ac.jp/KamLAND/chi2map_3rdresult/chi2map.html . Fig. 3
(low E spectrum) was dropped due to space limitation
Business constraints and growth potential of micro and small manufacturing enterprises in Uganda
Ugandan micro and small enterprises (MSEs) still perform poorly. Studies associating poor performance of manufacturers with lack of finance and low investment ignore micro enterprises. Those focusing on MSEs are either exploratory in nature or employ a descriptive analysis, which cannot show the extent to which business constraints explain the performance of MSEs. Thus, this paper tries to examine the extent to which the growth of MSEs is associated with business constraints while controlling for owners’ attributes and firms’ characteristics. The results reveal that MSEs’ growth potential is negatively associated with limited access to productive resources (finance and business development services), high taxes and lack of market access
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