Dark matter search results from the complete exposure of the PICO-60 C 3 F 8 bubble chamber

• Published in: Physical review. D 2019-07, Vol.100 (2)
• Main Authors: Amole, C., Ardid, M., Arnquist, I. J., Asner, D. M., Baxter, D., Behnke, E., Bressler, M., Broerman, B., Cao, G., Chen, C. J., Chowdhury, U., Clark, K., Collar, J. I., Cooper, P. S., Coutu, C. B., Cowles, C., Crisler, M., Crowder, G., Cruz-Venegas, N. A., Dahl, C. E., Das, M., Fallows, S., Farine, J., Felis, I., Filgas, R., Girard, F., Giroux, G., Hall, J., Hardy, C., Harris, O., Hillier, T., Hoppe, E. W., Jackson, C. M., Jin, M., Klopfenstein, L., Kozynets, T., Krauss, C. B., Laurin, M., Lawson, I., Leblanc, A., Levine, I., Licciardi, C., Lippincott, W. H., Loer, B., Mamedov, F., Mitra, P., Moore, C., Nania, T., Neilson, R., Noble, A. J., Oedekerk, P., Ortega, A., Piro, M. -C., Plante, A., Podviyanuk, R., Priya, S., Robinson, A. E., Sahoo, S., Scallon, O., Seth, S., Sonnenschein, A., Starinski, N., Štekl, I., Sullivan, T., Tardif, F., Vázquez-Jáuregui, E., Walkowski, N., Weima, E., Wichoski, U., Wierman, K., 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: 2470-0010; 2470-0029
• DOI: 10.1103/PhysRevD.100.022001

Final results are reported from operation of the PICO-60 C3F8 dark matter detector, a bubble chamber filled with 52 kg of C3F8 located in the SNOLAB underground laboratory. The chamber was operated at thermodynamic thresholds as low as 1.2 keV without loss of stability. A new blind 1404-kg-day exposure at 2.45 keV threshold was acquired with approximately the same expected total background rate as the previous 1167-kg-day exposure at 3.3 keV. This increased exposure is enabled in part by a new optical tracking analysis to better identify events near detector walls, permitting a larger fiducial volume. These results set the most stringent direct-detection constraint to date on the weakly interacting massive particle (WIMP)-proton spin-dependent cross section at $3.2×10^{-41}$ cm2 for a 25 GeV WIMP, improving on previous PICO results for 3–5 GeV WIMPs by an order of magnitude.