Dark Matter Search Results from the PICO-2L C3F8 Bubble Chamber

New data are reported from the operation of a 2 liter C3F8 bubble chamber in the SNOLAB underground laboratory, with a total exposure of 211.5 kg days at four different energy thresholds below 10 keV. These data show that C3F8 provides excellent electron-recoil and alpha rejection capabilities at very low thresholds. The chamber exhibits an electron-recoil sensitivity of 98.2%. These data also include the first observation of a dependence of acoustic signal on alpha energy. Twelve single nuclear recoil event candidates were observed during the run. The candidate events exhibit timing characteristics that are not consistent with the hypothesis of a uniform time distribution, and no evidence for a dark matter signal is claimed. These data provide the most sensitive direct detection constraints on WIMP-proton spin-dependent scattering to date, with significant sensitivity at low WIMP masses for spin-independent WIMP-nucleon scattering.The PICO Collaboration would like to thank SNOLAB and its staff for providing an exceptional underground laboratory space and invaluable technical support. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics under award 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 also acknowledge support from the Kavli Institute for Cosmological Physics at the University of Chicago. We acknowledge the financial support of the Spanish Ministerio de Economia y Competitividad, Consolider MultiDark CSD2009-00064 Grant. We acknowledge support from the Department of Atomic Energy (DAE), Government of India, under the Center for AstroParticle Physics II project (CAPP-II) at Saha Insititute of Nuclear Physics (SINP), Kolkata. We acknowledge the Czech Ministry of Education, Youth and Sports, Grant No. LM2011027. We acknowledge technical assistance from Fermilab's Computing, Particle Physics, and Accelerator Divisions, and from A. Behnke at IUSB.Amole, C.; Ardid Ramírez, M.; Asner, DM.; Baxter, D.; Behnke, E.; Bhattacharjee, P.; Borsodi, H.... (2015). Dark Matter Search Results from the PICO-2L C3F8 Bubble Chamber. Physical Review Letters. 114(2313):1-6. https://doi.org/10.1103/PhysRevLett.114.231302S161142313Komatsu, E., Dunkley, J., Nolta, M. R., Bennett, C. L., Gold, B., Hinshaw, G., … Wright, E. L. (2009). FIVE-YEARWILKINSON MICROWAVE ANISOTROPY PROBEOBSERVATIONS: COSMOLOGICAL INTERPRETATION. The Astrophysical Journal Supplement Series, 180(2), 330-376. doi:10.1088/0067-0049/180/2/330Jungman, G., Kamionkowski, M., & Griest, K. (1996). Supersymmetric dark matter. Physics Reports, 267(5-6), 195-373. doi:10.1016/0370-1573(95)00058-5Bertone, G., Hooper, D., & Silk, J. (2005). Particle dark matter: evidence, candidates and constraints. Physics Reports, 405(5-6), 279-390. doi:10.1016/j.physrep.2004.08.031Feng, J. L. (2010). Dark Matter Candidates from Particle Physics and Methods of Detection. Annual Review of Astronomy and Astrophysics, 48(1), 495-545. doi:10.1146/annurev-astro-082708-101659Goodman, M. W., & Witten, E. (1985). Detectability of certain dark-matter candidates. Physical Review D, 31(12), 3059-3063. doi:10.1103/physrevd.31.3059Behnke, E., Behnke, J., Brice, S. J., Broemmelsiek, D., Collar, J. I., … Conner, A. (2012). First dark matter search results from a 4-kgCF3Ibubble chamber operated in a deep underground site. Physical Review D, 86(5). doi:10.1103/physrevd.86.052001Behnke, E., Behnke, J., Brice, S. J., Broemmelsiek, D., Collar, J. I., … Cooper, P. S. (2011). Improved Limits on Spin-Dependent WIMP-Proton Interactions from a Two LiterCF3IBubble Chamber. Physical Review Letters, 106(2). doi:10.1103/physrevlett.106.021303Archambault, S., Behnke, E., Bhattacharjee, P., Bhattacharya, S., Dai, X., Das, M., … Zacek, V. (2012). Constraints on low-mass WIMP interactions on 19F from PICASSO. Physics Letters B, 711(2), 153-161. doi:10.1016/j.physletb.2012.03.078Felizardo, M., Girard, T. A., Morlat, T., Fernandes, A. C., Ramos, A. R., Marques, J. G., … Marques, R. (2014). The SIMPLE Phase II dark matter search. Physical Review D, 89(7). doi:10.1103/physrevd.89.072013Glaser, D. A., & Rahm, D. C. (1955). Characteristics of Bubble Chambers. Physical Review, 97(2), 474-479. doi:10.1103/physrev.97.474Seitz, F. (1958). On the Theory of the Bubble Chamber. Physics of Fluids, 1(1), 2. doi:10.1063/1.1724333Behnke, E., Benjamin, T., Brice, S. J., Broemmelsiek, D., Collar, J. I., … Cooper, P. S. (2013). Direct measurement of the bubble-nucleation energy threshold in aCF3Ibubble chamber. Physical Review D, 88(2). doi:10.1103/physrevd.88.021101Agostinelli, S., Allison, J., Amako, K., Apostolakis, J., Araujo, H., Arce, P., … Barrand, G. (2003). Geant4—a simulation toolkit. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 506(3), 250-303. doi:10.1016/s0168-9002(03)01368-8Allison, J., Amako, K., Apostolakis, J., Araujo, H., Arce Dubois, P., Asai, M., … Chytracek, R. (2006). Geant4 developments and applications. IEEE Transactions on Nuclear Science, 53(1), 270-278. doi:10.1109/tns.2006.869826Aubin, F., Auger, M., Genest, M.-H., Giroux, G., Gornea, R., Faust, R., … Storey, C. (2008). Discrimination of nuclear recoils from alpha particles with superheated liquids. New Journal of Physics, 10(10), 103017. doi:10.1088/1367-2630/10/10/103017Archambault, S., Aubin, F., Auger, M., Beleshi, M., Behnke, E., … Behnke, J. (2011). New insights into particle detection with superheated liquids. New Journal of Physics, 13(4), 043006. doi:10.1088/1367-2630/13/4/043006Pozzi, S. A., Padovani, E., & Marseguerra, M. (2003). MCNP-PoliMi: a Monte-Carlo code for correlation measurements. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 513(3), 550-558. doi:10.1016/j.nima.2003.06.012Robinson, A. E. (2014). New libraries for simulating neutron scattering in dark matter detector calibrations. Physical Review C, 89(3). doi:10.1103/physrevc.89.032801Yellin, S. (2002). Finding an upper limit in the presence of an unknown background. Physical Review D, 66(3). doi:10.1103/physrevd.66.032005Lewin, J. D., & Smith, P. F. (1996). Review of mathematics, numerical factors, and corrections for dark matter experiments based on elastic nuclear recoil. Astroparticle Physics, 6(1), 87-112. doi:10.1016/s0927-6505(96)00047-3Tovey, D. R., Gaitskell, R. J., Gondolo, P., Ramachers, Y., & Roszkowski, L. (2000). A new model-independent method for extracting spin-dependent cross section limits from dark matter searches. Physics Letters B, 488(1), 17-26. doi:10.1016/s0370-2693(00)00846-7Roszkowski, L., Austri, R. R. de, & Trotta, R. (2007). Implications for the Constrained MSSM from a new prediction forb→sγ. Journal of High Energy Physics, 2007(07), 075-075. doi:10.1088/1126-6708/2007/07/075Aprile, E., Alfonsi, M., Arisaka, K., Arneodo, F., Balan, C., Baudis, L., … Bokeloh, K. (2013). Limits on Spin-Dependent WIMP-Nucleon Cross Sections from 225 Live Days of XENON100 Data. Physical Review Letters, 111(2). doi:10.1103/physrevlett.111.021301Aartsen, M. G., Abbasi, R., Abdou, Y., Ackermann, M., Adams, J., Aguilar, J. A., … Bai, X. (2013). Search for Dark Matter Annihilations in the Sun with the 79-String IceCube Detector. Physical Review Letters, 110(13). doi:10.1103/physrevlett.110.131302Tanaka, T., Abe, K., Hayato, Y., Iida, T., Kameda, J., Koshio, Y., … Nakahata, M. (2011). AN INDIRECT SEARCH FOR WEAKLY INTERACTING MASSIVE PARTICLES IN THE SUN USING 3109.6 DAYS OF UPWARD-GOING MUONS IN SUPER-KAMIOKANDE. The Astrophysical Journal, 742(2), 78. doi:10.1088/0004-637x/742/2/78Chatrchyan, S., Khachatryan, V., Sirunyan, A. M., Tumasyan, A., Adam, W., Bergauer, T., … Friedl, M. (2012). Search for Dark Matter and Large Extra Dimensions inppCollisions Yielding a Photon and Missing Transverse Energy. Physical Review Letters, 108(26). doi:10.1103/physrevlett.108.261803First results on dark matter annihilation in the Sun using the ANTARES neutrino telescope. (2013). Journal of Cosmology and Astroparticle Physics, 2013(11), 032-032. doi:10.1088/1475-7516/2013/11/032Demidov, S., & Suvorova, O. (2010). Annihilation of NMSSM neutralinos in the Sun and neutrino telescope limits. Journal of Cosmology and Astroparticle Physics, 2010(06), 018-018. doi:10.1088/1475-7516/2010/06/018Avrorin, A. D., Avrorin, A. V., Aynutdinov, V. M., Bannasch, R., Belolaptikov, I. A., Bogorodsky, D. Y., … Demidov, S. V. (2015). Search for neutrino emission from relic dark matter in the sun with the Baikal NT200 detector. Astroparticle Physics, 62, 12-20. doi:10.1016/j.astropartphys.2014.07.006Akerib, D. S., Araújo, H. M., Bai, X., Bailey, A. J., Balajthy, J., Bedikian, S., … Bradley, A. (2014). First Results from the LUX Dark Matter Experiment at the Sanford Underground Research Facility. Physical Review Letters, 112(9). doi:10.1103/physrevlett.112.091303Agnese, R., Anderson, A. J., Asai, M., Balakishiyeva, D., Basu Thakur, R., Bauer, D. A., … Bowles, M. A. (2014). Search for Low-Mass Weakly Interacting Massive Particles with SuperCDMS. Physical Review Letters, 112(24). doi:10.1103/physrevlett.112.241302Agnese, R., Anderson, A. J., Asai, M., Balakishiyeva, D., Basu Thakur, R., Bauer, D. A., … Brandt, D. (2014). Search for Low-Mass Weakly Interacting Massive Particles Using Voltage-Assisted Calorimetric Ionization Detection in the SuperCDMS Experiment. Physical Review Letters, 112(4). doi:10.1103/physrevlett.112.041302Angle, J., Aprile, E., Arneodo, F., Baudis, L., Bernstein, A., … Bolozdynya, A. I. (2011). Search for Light Dark Matter in XENON10 Data. Physical Review Letters, 107(5). doi:10.1103/physrevlett.107.051301Aprile, E., Alfonsi, M., Arisaka, K., Arneodo, F., Balan, C., Baudis, L., … Bokeloh, K. (2012). Dark Matter Results from 225 Live Days of XENON100 Data. Physical Review Letters, 109(18). doi:10.1103/physrevlett.109.181301Angloher, G., Bento, A., Bucci, C., Canonica, L., Erb, A., von Feilitzsch, F., … Zöller, A. (2014). Results on low mass WIMPs using an upgraded CRESST-II detector. The European Physical Journal C, 74(12). doi:10.1140/epjc/s10052-014-3184-9Bernabei, R., Belli, P., Cappella, F., Cerulli, R., Dai, C. J., d’ Angelo, A., … Ye, Z. P. (2008). First results from DAMA/LIBRA and the combined results with DAMA/NaI. The European Physical Journal C, 56(3), 333-355. doi:10.1140/epjc/s10052-008-0662-yAalseth, C. E., Barbeau, P. S., Colaresi, J., Collar, J. I., Diaz Leon, J., … Fast, J. E. (2013). CoGeNT: A search for low-mass dark matter usingp-type point contact germanium detectors. Physical Review D, 88(1). doi:10.1103/physrevd.88.012002Agnese, R., Ahmed, Z., Anderson, A. J., Arrenberg, S., Balakishiyeva, D., Basu Thakur, R., … Brink, P. L. (2013). Silicon detector results from the first five-tower run of CDMS II. Physical Review D, 88(3). doi:10.1103/physrevd.88.03110