Dark matter search results from the PICO-60 CF3I bubble chamber

Autor: Amole, C., Ardid Ramírez, Miguel, Asner, D. M., Baxter, D., Behnke, E., Bhattacharjee, P., Borsodi, H., Bou Cabo, Manuel, Brice, S. J., Broemmelsiek, D., Clark, K., Collar, J. I., Cooper, P. S., Crisler, M., Felis Enguix, Iván
Jazyk: angličtina
Rok vydání: 2016
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Zdroj: RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
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Popis: New data are reported from the operation of the PICO-60 dark matter detector, a bubble chamber filled with 36.8 kg of CF3I and located in the SNOLAB underground laboratory. PICO-60 is the largest bubble chamber to search for dark matter to date. With an analyzed exposure of 92.8 livedays, PICO-60 exhibits the same excellent background rejection observed in smaller bubble chambers. Alpha decays in PICO-60 exhibit frequency-dependent acoustic calorimetry, similar but not identical to that reported recently in a C3F8 bubble chamber. PICO-60 also observes a large population of unknown background events, exhibiting acoustic, spatial, and timing behaviors inconsistent with those expected from a dark matter signal. These behaviors allow for analysis cuts to remove all background events while retaining 48.2% of the exposure. Stringent limits on weakly interacting massive particles interacting via spin-dependent proton and spin-independent processes are set, and most interpretations of the DAMA/LIBRA modulation signal as dark matter interacting with iodine nuclei are ruled out.
The PICO Collaboration would like to thank SNOLAB and its staff for providing an exceptional underground laboratory space and invaluable technical support. We acknowledge technical assistance from Fermilab's Computing, Particle Physics, and Accelerator Divisions and from A. Behnke at IUSB. We thank V. Gluscevic and S. McDermott for useful conversations and their assistance with the DMDD code package. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award No. DE-SC-0012161. Fermi National Accelerator Laboratory is operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359. Part of the research described in this paper was conducted under the Ultra Sensitive Nuclear Measurements Initiative at Pacific Northwest National Laboratory, a multiprogram national laboratory operated by Battelle for the U.S. Department of Energy. We acknowledge the National Science Foundation for their support including Grants No. PHY-1242637, No. PHY-0919526, and No. PHY-1205987. We acknowledge the support of the National Sciences and Engineering Research Council of Canada (NSERC) and the Canada Foundation for Innovation (CFI). We thank the Kavli Institute for Cosmological Physics at the University of Chicago. We were also supported by the Spanish Ministerio de Economia y Competitividad, Consolider MultiDark CSD2009-00064 Grant. We thank the Department of Atomic Energy (DAE), Government of India, under the project CAPP-II at SINP, Kolkata. We acknowledge the Czech Ministry of Education, Youth and Sports, Grant No. LM2011027.
Databáze: OpenAIRE
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