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. / Thesis (Ph.D, Physics, Engineering Physics and Astronomy) -- Queen's University, 2008-08-29 11:42:31.428
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/5323 |
| Date | 18 November 2009 |
| Creators | Clark, Kenneth |
| Contributors | Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.)) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Format | 1937481 bytes, application/pdf |
| Rights | This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
| Relation | Canadian theses |
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