title: Dark Matter Search Results from the PICO-2L C3F8 Bubble Chamber.
abstract: 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 <3.5×10(-10) and an alpha rejection factor 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.
authors.affiliation: Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Amole
authors.affiliation: Universitat Politècnica de València, IGIC, 46730 Gandia, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Ardid
authors.affiliation: Pacific Northwest National Laboratory, Richland, Washington 99354, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Asner
authors.affiliation: Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: D
authors.initials: D
authors.lastname: Baxter
authors.affiliation: Department of Physics and Astronomy, Indiana University South Bend, South Bend, Indiana 46634, USA.
authors.forename: E
authors.initials: E
authors.lastname: Behnke
authors.affiliation: Saha Institute of Nuclear Physics, Astroparticle Physics and Cosmology Division, Kolkata, West Bengal 700064, India.
authors.forename: P
authors.initials: P
authors.lastname: Bhattacharjee
authors.affiliation: Department of Physics and Astronomy, Indiana University South Bend, South Bend, Indiana 46634, USA.
authors.forename: H
authors.initials: H
authors.lastname: Borsodi
authors.affiliation: Universitat Politècnica de València, IGIC, 46730 Gandia, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Bou-Cabo
authors.affiliation: Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Brice
authors.affiliation: Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
authors.forename: D
authors.initials: D
authors.lastname: Broemmelsiek
authors.affiliation: Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada.
authors.forename: K
authors.initials: K
authors.lastname: Clark
authors.affiliation: Enrico Fermi Institute, KICP and Department of Physics, University of Chicago, Chicago, Illinois 60637, USA.
authors.forename: J I
authors.initials: JI
authors.lastname: Collar
authors.affiliation: Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
authors.forename: P S
authors.initials: PS
authors.lastname: Cooper
authors.affiliation: Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
authors.forename: M
authors.initials: M
authors.lastname: Crisler
authors.affiliation: Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA.|Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
authors.forename: C E
authors.initials: CE
authors.lastname: Dahl
authors.affiliation: Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Daley
authors.affiliation: Saha Institute of Nuclear Physics, Astroparticle Physics and Cosmology Division, Kolkata, West Bengal 700064, India.
authors.forename: M
authors.initials: M
authors.lastname: Das
authors.affiliation: Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7, Canada.
authors.forename: F
authors.initials: F
authors.lastname: Debris
authors.affiliation: Department of Physics, Laurentian University, Sudbury, Ontario P3E 2C6, Canada.
authors.forename: N
authors.initials: N
authors.lastname: Dhungana
authors.affiliation: Department of Physics, Laurentian University, Sudbury, Ontario P3E 2C6, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Farine
authors.affiliation: Universitat Politècnica de València, IGIC, 46730 Gandia, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Felis
authors.affiliation: Institute of Experimental and Applied Physics, Czech Technical University in Prague, Prague 12800, Czech Republic.
authors.forename: R
authors.initials: R
authors.lastname: Filgas
authors.affiliation: Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Fines-Neuschild
authors.affiliation: Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7, Canada.
authors.forename: F
authors.initials: F
authors.lastname: Girard
authors.affiliation: Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada.
authors.forename: G
authors.initials: G
authors.lastname: Giroux
authors.affiliation: Enrico Fermi Institute, KICP and Department of Physics, University of Chicago, Chicago, Illinois 60637, USA.
authors.forename: M
authors.initials: M
authors.lastname: Hai
authors.affiliation: Pacific Northwest National Laboratory, Richland, Washington 99354, USA.
authors.forename: J
authors.initials: J
authors.lastname: Hall
authors.affiliation: Department of Physics and Astronomy, Indiana University South Bend, South Bend, Indiana 46634, USA.
authors.forename: O
authors.initials: O
authors.lastname: Harris
authors.affiliation: Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7, Canada.
authors.forename: C M
authors.initials: CM
authors.lastname: Jackson
authors.affiliation: Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: M
authors.initials: M
authors.lastname: Jin
authors.affiliation: Department of Physics, University of Alberta, Edmonton, Alberta T6G 2G7, Canada.
authors.forename: C B
authors.initials: CB
authors.lastname: Krauss
authors.affiliation: Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Lafrenière
authors.affiliation: Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Laurin
authors.affiliation: Department of Physics, Laurentian University, Sudbury, Ontario P3E 2C6, Canada.|SNOLAB, Lively, Ontario P3Y 1N2, Canada.
authors.forename: I
authors.initials: I
authors.lastname: Lawson
authors.affiliation: Department of Physics and Astronomy, Indiana University South Bend, South Bend, Indiana 46634, USA.
authors.forename: I
authors.initials: I
authors.lastname: Levine
authors.affiliation: Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
authors.forename: W H
authors.initials: WH
authors.lastname: Lippincott
authors.affiliation: Department of Physics and Astronomy, Indiana University South Bend, South Bend, Indiana 46634, USA.
authors.forename: E
authors.initials: E
authors.lastname: Mann
authors.affiliation: Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7, Canada.
authors.forename: J P
authors.initials: JP
authors.lastname: Martin
authors.affiliation: Bio-Inspired Materials and Devices Laboratory (BMDL), Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061, USA.
authors.forename: D
authors.initials: D
authors.lastname: Maurya
authors.affiliation: Department of Physics, University of Alberta, Edmonton, Alberta T6G 2G7, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Mitra
authors.affiliation: Enrico Fermi Institute, KICP and Department of Physics, University of Chicago, Chicago, Illinois 60637, USA.|Department of Physics, Drexel University, Philadelphia, Pennsylvania 19104, USA.
authors.forename: R
authors.initials: R
authors.lastname: Neilson
authors.affiliation: Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada.
authors.forename: A J
authors.initials: AJ
authors.lastname: Noble
authors.affiliation: Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Plante
authors.affiliation: Department of Physics, Laurentian University, Sudbury, Ontario P3E 2C6, Canada.
authors.forename: R B
authors.initials: RB
authors.lastname: Podviianiuk
authors.affiliation: Bio-Inspired Materials and Devices Laboratory (BMDL), Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061, USA.
authors.forename: S
authors.initials: S
authors.lastname: Priya
authors.affiliation: Enrico Fermi Institute, KICP and Department of Physics, University of Chicago, Chicago, Illinois 60637, USA.
authors.forename: A E
authors.initials: AE
authors.lastname: Robinson
authors.affiliation: Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
authors.forename: M
authors.initials: M
authors.lastname: Ruschman
authors.affiliation: Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7, Canada.|Department of Physics, Laurentian University, Sudbury, Ontario P3E 2C6, Canada.
authors.forename: O
authors.initials: O
authors.lastname: Scallon
authors.affiliation: Saha Institute of Nuclear Physics, Astroparticle Physics and Cosmology Division, Kolkata, West Bengal 700064, India.
authors.forename: S
authors.initials: S
authors.lastname: Seth
authors.affiliation: Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
authors.forename: A
authors.initials: A
authors.lastname: Sonnenschein
authors.affiliation: Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7, Canada.
authors.forename: N
authors.initials: N
authors.lastname: Starinski
authors.affiliation: Institute of Experimental and Applied Physics, Czech Technical University in Prague, Prague 12800, Czech Republic.
authors.forename: I
authors.initials: I
authors.lastname: Štekl
authors.affiliation: Department of Physics, Laurentian University, Sudbury, Ontario P3E 2C6, Canada.|SNOLAB, Lively, Ontario P3Y 1N2, Canada.|Instituto de Física, Universidad Nacional Autónoma de México, México D. F. 01000, México.
authors.forename: E
authors.initials: E
authors.lastname: Vázquez-Jáuregui
authors.affiliation: Department of Physics and Astronomy, Indiana University South Bend, South Bend, Indiana 46634, USA.
authors.forename: J
authors.initials: J
authors.lastname: Wells
authors.affiliation: Department of Physics, Laurentian University, Sudbury, Ontario P3E 2C6, Canada.
authors.forename: U
authors.initials: U
authors.lastname: Wichoski
authors.affiliation: Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7, Canada.
authors.forename: V
authors.initials: V
authors.lastname: Zacek
authors.affiliation: Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: J
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000162:Acoustics / Q000295:instrumentation; D000465:Algorithms; D005466:Fluorocarbons / Q000737:chemistry*; D008962:Models, Theoretical; D009502:Neutrons
chemical_list: D005466:Fluorocarbons; C042852:perflutren