Dark Matter Search Results from the PICO − 60   C 3 F 8 Bubble Chamber

• Published in: Physical review letters 2017-06, Vol.118 (25), Article 251301
• Main Authors: Amole, C., Ardid, M., Arnquist, I. J., Asner, D. M., Baxter, D., Behnke, E., Bhattacharjee, P., Borsodi, H., Bou-Cabo, M., Campion, P., Cao, G., Chen, C. J., Chowdhury, U., Clark, K., Collar, J. I., Cooper, P. S., Crisler, M., Crowder, G., Dahl, C. E., Das, M., Fallows, S., Farine, J., Felis, I., Filgas, R., Girard, F., Giroux, G., Hall, J., Harris, O., Hoppe, E. W., Jin, M., Krauss, C. B., Laurin, M., Lawson, I., Leblanc, A., Levine, I., Lippincott, W. H., Mamedov, F., Maurya, D., Mitra, P., Nania, T., Neilson, R., Noble, A. J., Olson, S., Ortega, A., Plante, A., Podviyanuk, R., Priya, S., Robinson, A. E., Roeder, A., Rucinski, R., Scallon, O., Seth, S., Sonnenschein, A., Starinski, N., Štekl, I., Tardif, F., Vázquez-Jáuregui, E., Wells, J., Wichoski, U., Yan, Y., Zacek, V., Zhang, J.
• Format: Article
• Language: English
• Subjects: ASTRONOMY AND ASTROPHYSICS; INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.118.251301

New results are reported from the operation of the PICO-60 dark matter detector, a bubble chamber filled with 52 kg of C3F8 located in the SNOLAB underground laboratory. As in previous PICO bubble chambers, PICO-60 C3F8 exhibits excellent electron recoil and alpha decay rejection, and the observed multiple-scattering neutron rate indicates a single-scatter neutron background of less than one event per month. A blind analysis of an efficiency-corrected 1167-kg day exposure at a 3.3-keV thermodynamic threshold reveals no single-scattering nuclear recoil candidates, consistent with the predicted background. In conclusion, these results set the most stringent direct-detection constraint to date on the weakly interacting massive particle (WIMP)-proton spin-dependent cross section at 3.4×10-41 cm2 for a 30-GeV c-2 WIMP, more than 1 order of magnitude improvement from previous PICO results.