dc.contributor.author Kamaha, Alvine dc.contributor.other Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.)) en dc.date 2015-03-13 16:25:08.295 en dc.date.accessioned 2015-03-16T20:56:43Z dc.date.available 2015-03-16T20:56:43Z dc.date.issued 2015-03-16 dc.identifier.uri http://hdl.handle.net/1974/12780 dc.description Thesis (Ph.D, Physics, Engineering Physics and Astronomy) -- Queen's University, 2015-03-13 16:25:08.295 en dc.description.abstract The final results of the PICASSO experiment, with 409 kg days of exposure collected from November 2012 to January 2014, have yielded new limits for Spin-Dependent and Spin-Independent Dark Matter interactions.\\ en_US The data collected and the various backgrounds were assiduously studied using Monte Carlo simulations and a new set of sophisticated analysis techniques including the wavelet analysis presented in this thesis. In general, a good suppression of most backgrounds was attained. The neutron background event rate was reduced to about a factor of 10 compared to the previous phase of the experiment. Electronic and acoustic noise events were thoroughly suppressed. A new class of mystery events'' were removed as well. All that remained was the irreducible alpha background.\\ No signal consistent with a WIMP Dark Matter hypothesis was observed. Consequently, an exclusion curve was obtained with a minimum limit at ${90\%}$ C.L. of ${\sigma_{\chi p}^{SD} =0.0228}$ pb at a WIMP mass of 20 GeV/$c^2$ in the Spin-Dependent sector. By combining results from 2012 and the current results, an improved constraint of ${\sigma_{\chi p}^{SD}}$(90${\%}$ C.L.) ${=0.0188}$ pb at 20 GeV/$c^2$ was placed on the Dark Matter interaction with protons in the Fluorine nuclei used in the detectors.\\ In addition, the new limits on WIMP-proton interactions in the Spin Independent sector exclude the DAMA/LIBRA results (at ${90\%}$ C.L.) for low masses below 12 GeV/$c^2$ and further constrain the published CRESST and CDMS Si discovery regions at low WIMP masses. dc.language en en dc.language.iso en en_US dc.relation.ispartofseries Canadian theses en dc.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. en dc.subject Dark Matter searches en_US dc.title Improved Limits On The Existence Of Dark Matter. The Final Results From The PICASSO Experiment. en_US dc.type thesis en_US dc.description.degree Ph.D en dc.contributor.supervisor Noble, Anthony J. en dc.contributor.department Physics, Engineering Physics and Astronomy en
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