Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.509994
Title: Data analysis and results of the upgraded CRESST dark matter search
Author: McGowan, Richard
Awarding Body: University of Oxford
Current Institution: University of Oxford
Date of Award: 2010
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Abstract:
CRESST has an established analysis procedure to evaluate the energy of the events it detects, in an attempt to detect WIMP dark matter. It was shown that unless eight classes of contaminant event were removed prior to this analysis, the output energy spectrum would be significantly biased. For both scientific and practical reasons, the removal process should be blind, and a series of cuts were developed to flag these events automatically, without removing any true events. An event simulation package was developed to optimise these cuts. It was shown that noise fluctuations could also reduce CRESST’s sensitivity, so a noise-dependent acceptance region was introduced to resolve this. The upgraded CRESST experiment included a new electronics system to provide heating and bias currents for 66 detectors. This system was integrated into the CRESST set-up, and it was shown that the electronics contributed no extra noise to the detectors. Data with an exposure of 50 kg days were analysed using the cuts and the noise-dependent acceptance. The cuts were successful, with no contaminant event retained and a live time reduction of just 2.3%. The data were used to set an upper limit on the WIMP-nucleon cross section for elastic scattering with a minimum of 6.3 × 10^(−7) pb at a WIMP mass of 61 GeV. This is a factor of 2.5 better than the previous best CRESST limit.
Supervisor: Kraus, Hans Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.509994  DOI: Not available
Keywords: Particle physics ; dark matter ; OxRop ; neutralino ; limit ; robust analysis
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