Maximum likelihood analysis of low energy CDMS II germanium data
Abstract
We report on the results of a search for a Weakly Interacting Massive Particle (WIMP) signal in low-energy data of the Cryogenic Dark Matter Search experiment using a maximum likelihood analysis. A background model is constructed using GEANT4 to simulate the surface-event background from ^(210)Pb decay-chain events, while using independent calibration data to model the gamma background. Fitting this background model to the data results in no statistically significant WIMP component. In addition, we perform fits using an analytic ad hoc background model proposed by Collar and Fields, who claimed to find a large excess of signal-like events in our data. We confirm the strong preference for a signal hypothesis in their analysis under these assumptions, but excesses are observed in both single- and multiple-scatter events, which implies the signal is not caused by WIMPs, but rather reflects the inadequacy of their background model.
Additional Information
© 2015 American Physical Society. Received 10 October 2014; published 30 March 2015. The CDMS Collaboration gratefully acknowledges the contributions of numerous engineers and technicians; we would like to especially thank Dennis Seitz, Jim Beaty, Bruce Hines, Larry Novak, Richard Schmitt, Astrid Tomada, and John Emes. In addition, we gratefully acknowledge assistance from the staff of the Soudan Underground Laboratory and the Minnesota Department of Natural Resources. This work is supported in part by the National Science Foundation, by the United States Department of Energy, by NSERC Canada, and by MultiDark (Spanish MINECO). Fermilab is operated by the Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359. SLAC is operated under Contract No. DE-AC02-76SF00515 with the United States Department of Energy.Attached Files
Published - PhysRevD.91.052021.pdf
Submitted - 1410.1003v1.pdf
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Additional details
- Eprint ID
- 57167
- Resolver ID
- CaltechAUTHORS:20150501-151404970
- NSF
- Natural Sciences and Engineering Research Council of Canada (NSERC)
- MultiDark
- Ministerio de Economía y Competitividad (MINECO)
- DE-AC02-07CH11359
- Department of Energy (DOE)
- DE-AC02-76SF00515
- Department of Energy (DOE)
- Created
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2015-05-04Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field