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|Title: ||A New and Improved Spin-Dependent Dark Matter Exclusion Limit Using the PICASSO Experiment|
|Authors: ||Clark, Kenneth|
|Keywords: ||dark matter|
|Issue Date: ||2009|
|Series/Report no.: ||Canadian theses|
|Abstract: ||The PICASSO project is a direct dark matter search experiment located 2070 metres underground in SNOLAB. Superheated droplets of Freon (C4F10) are used as the active mass, providing a target for the incoming neutralinos. Recoiling nuclei deposit energy in the superheated Freon droplets, triggering a phase transition, the pressure waves of which can be detected using piezo-electric sensors.
Previously published limits using an exposure of 1.98 +/- 0.19 kg day obtained a peak spin-dependent cross section exclusion limit for neutralino-proton interactions of 1.31 pb at a neutralino mass of 29 GeV/c^2 at a 90% confidence level. Improvements in the detectors installed in the underground experiment have provided 20.99 +/- 0.25 kg day for analysis and improvements in the analysis method have produced an exclusion limit of 2.9 X 10^(-2) pb at a neutralino mass of 16.7 GeV/c^2.
In addition, a thorough study of the backgrounds, corrections and systematic uncertainties has been included, indicating that this limit does not exceed 3.5 X 10^(-2) pb when considering the one sigma error on the uncertainty band.|
|Description: ||Thesis (Ph.D, Physics, Engineering Physics and Astronomy) -- Queen's University, 2008-08-29 11:42:31.428|
|Appears in Collections:||Queen's Theses & Dissertations|
Physics, Engineering Physics & Astronomy Graduate Theses
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