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39 results on '"Boulay, MG"'

1. Search for hep solar neutrinos and the diffuse supernova neutrino background using all three phases of the Sudbury Neutrino Observatory

Author

Aharmim, B, Ahmed, SN, Anthony, AE, Barros, N, Beier, EW, Bellerive, A, Beltran, B, Bergevin, M, Biller, SD, Blucher, E, Bonventre, R, Boudjemline, K, Boulay, MG, Cai, B, Callaghan, EJ, Caravaca, J, Chan, YD, Chauhan, D, Chen, M, Cleveland, BT, Cox, GA, Dai, X, Deng, H, Descamps, FB, Detwiler, JA, Doe, PJ, Doucas, G, Drouin, PL, Dunford, M, Elliott, SR, Evans, HC, Ewan, GT, Farine, J, Fergani, H, Fleurot, F, Ford, RJ, Formaggio, JA, Gagnon, N, Gilje, K, Goon, JTM, Graham, K, Guillian, E, Habib, S, Hahn, RL, Hallin, AL, Hallman, ED, Harvey, PJ, Hazama, R, Heintzelman, WJ, Heise, J, Helmer, RL, Hime, A, Howard, C, Huang, M, Jagam, P, Jamieson, B, Jelley, NA, Jerkins, M, Keeter, KJ, Klein, JR, Kormos, LL, Kos, M, Kraus, C, Krauss, CB, Krüger, A, Kutter, T, Kyba, CCM, Labe, K, Land, BJ, Lange, R, Latorre, A, Law, J, Lawson, IT, Lesko, KT, Leslie, JR, Levine, I, Loach, JC, Maclellan, R, Majerus, S, Mak, HB, Maneira, J, Martin, RD, Mastbaum, A, McCauley, N, McDonald, AB, McGee, SR, Miller, ML, Monreal, B, Monroe, J, Nickel, BG, Noble, AJ, O'Keeffe, HM, Oblath, NS, Okada, CE, Ollerhead, RW, Orebi Gann, GD, Oser, SM, Ott, RA, Peeters, SJM, and Poon, AWP

Subjects
hep-ex, nucl-ex
Abstract

A search has been performed for neutrinos from two sources, the hep reaction in the solar pp fusion chain and the νe component of the diffuse supernova neutrino background (DSNB), using the full dataset of the Sudbury Neutrino Observatory with a total exposure of 2.47 kton-years after fiducialization. The hep search is performed using both a single-bin counting analysis and a likelihood fit. We find a best-fit flux that is compatible with solar model predictions while remaining consistent with zero flux, and set a one-sided upper limit of φhep

Published
2020

2. Cosmogenic neutron production at the Sudbury Neutrino Observatory

Author

Aharmim, B, Ahmed, SN, Anthony, AE, Barros, N, Beier, EW, Bellerive, A, Beltran, B, Bergevin, M, Biller, SD, Bonventre, R, Boudjemline, K, Boulay, MG, Cai, B, Callaghan, EJ, Caravaca, J, Chan, YD, Chauhan, D, Chen, M, Cleveland, BT, Cox, GA, Curley, R, Dai, X, Deng, H, Descamps, FB, Detwiler, JA, Doe, PJ, Doucas, G, Drouin, PL, Dunford, M, Elliott, SR, Evans, HC, Ewan, GT, Farine, J, Fergani, H, Fleurot, F, Ford, RJ, Formaggio, JA, Gagnon, N, Gilje, K, Goon, JTM, Graham, K, Guillian, E, Habib, S, Hahn, RL, Hallin, AL, Hallman, ED, Harvey, PJ, Hazama, R, Heintzelman, WJ, Heise, J, Helmer, RL, Hime, A, Howard, C, Huang, M, Jagam, P, Jamieson, B, Jelley, NA, Jerkins, M, Kéfélian, C, Keeter, KJ, Klein, JR, Kormos, LL, Kos, M, Krüger, A, Kraus, C, Krauss, CB, Kutter, T, Kyba, CCM, Land, BJ, Lange, R, Law, J, Lawson, IT, Lesko, KT, Leslie, JR, Levine, I, Loach, JC, MacLellan, R, Majerus, S, Mak, HB, Maneira, J, Martin, RD, Mastbaum, A, McCauley, N, McDonald, AB, McGee, SR, Miller, ML, Monreal, B, Monroe, J, Nickel, BG, Noble, AJ, O'Keeffe, HM, Oblath, NS, Okada, CE, Ollerhead, RW, Orebi Gann, GD, Oser, SM, Ott, RA, Peeters, SJM, Poon, AWP, and Prior, G

Subjects
hep-ex, nucl-ex
Abstract

Neutrons produced in nuclear interactions initiated by cosmic-ray muons present an irreducible background to many rare-event searches, even in detectors located deep underground. Models for the production of these neutrons have been tested against previous experimental data, but the extrapolation to deeper sites is not well understood. Here we report results from an analysis of cosmogenically produced neutrons at the Sudbury Neutrino Observatory. A specific set of observables are presented, which can be used to benchmark the validity of geant4 physics models. In addition, the cosmogenic neutron yield, in units of 10-4 cm2/(g·μ), is measured to be 7.28±0.09(stat)-1.12+1.59(syst) in pure heavy water and 7.30±0.07(stat)-1.02+1.40(syst) in NaCl-loaded heavy water. These results provide unique insights into this potential background source for experiments at SNOLAB.

Published
2019

3. Electromagnetic backgrounds and potassium-42 activity in the DEAP-3600 dark matter detector

Author

Ajaj, R, Araujo, GR, Batygov, M, Beltran, B, Bina, CE, Boulay, MG, Broerman, B, Bueno, JF, Burghardt, PM, Butcher, A, Cai, B, Cárdenas-Montes, M, Cavuoti, S, Chen, M, Chen, Y, Cleveland, BT, Dering, K, Duncan, FA, Dunford, M, Erlandson, A, Fatemighomi, N, Fiorillo, G, Flower, A, Ford, RJ, Gagnon, R, Gallacher, D, García Abia, P, Garg, S, Giampa, P, Goeldi, D, Golovko, VV, Gorel, P, Graham, K, Grant, DR, Hallin, AL, Hamstra, M, Harvey, PJ, Hearns, C, Joy, A, Jillings, CJ, Kamaev, O, Kaur, G, Kemp, A, Kochanek, I, Kuźniak, M, Langrock, S, La Zia, F, Lehnert, B, Li, X, Litvinov, O, Lock, J, Longo, G, Majewski, P, McDonald, AB, McElroy, T, McGinn, T, McLaughlin, JB, Mehdiyev, R, Mielnichuk, C, Monroe, J, Nadeau, P, Nantais, C, Ng, C, Noble, AJ, Ouellet, C, Pasuthip, P, Peeters, SJM, Pesudo, V, Piro, MC, Pollmann, TR, Rand, ET, Rethmeier, C, Retière, F, Sanchez García, E, Santorelli, R, Seeburn, N, Skensved, P, Smith, B, Smith, NJT, Sonley, T, Stainforth, R, Stone, C, Strickland, V, Sur, B, Vázquez-Jáuregui, E, Veloce, L, Viel, S, Walding, J, Waqar, M, Ward, M, Westerdale, S, Willis, J, and Zuñiga-Reyes, A

Subjects
nucl-ex, astro-ph.IM
Abstract

The DEAP-3600 experiment is searching for weakly interacting massive particles dark matter with a 3.3 ×103 kg single phase liquid argon (LAr) target, located 2.1 km underground at SNOLAB. The experimental signature of dark matter interactions is kilo electron volt-scale Ar40 nuclear recoils producing 128 nm LAr scintillation photons observed by photomultiplier tubes. The largest backgrounds in DEAP-3600 are electronic recoils (ERs) induced by β and γ rays originating from internal and external radioactivity in the detector material. A background model of the ER interactions in DEAP-3600 was developed and is described in this work. The model is based on several components which are expected from radioisotopes in the LAr, from ex situ material assay measurements, and from dedicated independent in situ analyses. This prior information is used in a Bayesian fit of the ER components to a 247.2 d dataset to model the radioactivity in the surrounding detector materials. Pulse-shape discrimination separates ER and NR events. However, detailed knowledge of the ER background and activity of detector components sets valuable constraints on NR backgrounds including neutrons and alphas. In addition, the activity of Ar42 in LAr in DEAP-3600 is determined by measuring the daughter decay of K42. This cosmogenically activated trace isotope is a relevant background at higher energies for other rare event searches using atmospheric argon, e.g., DarkSide-20k, GERDA, or LEGEND. The specific activity of Ar42 in the atmosphere is found to be 40.4±5.9 μBq/kg of argon.

Published
2019

4. Measurement of neutron production in atmospheric neutrino interactions at the Sudbury Neutrino Observatory

Author

Aharmim, B, Ahmed, SN, Anthony, AE, Barros, N, Beier, EW, Bellerive, A, Beltran, B, Bergevin, M, Biller, SD, Bonventre, R, Boudjemline, K, Boulay, MG, Cai, B, Callaghan, EJ, Caravaca, J, Chan, YD, Chauhan, D, Chen, M, Cleveland, BT, Cox, GA, Dai, X, Deng, H, Descamps, FB, Detwiler, JA, Doe, PJ, Doucas, G, Drouin, P-L, Dunford, M, Elliott, SR, Evans, HC, Ewan, GT, Farine, J, Fergani, H, Fleurot, F, Ford, RJ, Formaggio, JA, Gagnon, N, Gilje, K, Goon, JTM, Graham, K, Guillian, E, Habib, S, Hahn, RL, Hallin, AL, Hallman, ED, Harvey, PJ, Hazama, R, Heintzelman, WJ, Heise, J, Helmer, RL, Hime, A, Howard, C, Huang, M, Jagam, P, Jamieson, B, Jelley, NA, Jerkins, M, Keeter, KJ, Klein, JR, Kormos, LL, Kos, M, Kruger, A, Kraus, C, Krauss, CB, Kutter, T, Kyba, CCM, Land, BJ, Lange, R, Law, J, Lawson, IT, Lesko, KT, Leslie, JR, Levine, I, Loach, JC, MacLellan, R, Majerus, S, Mak, HB, Maneira, J, Martin, RD, Mastbaum, A, McCauley, N, McDonald, AB, McGee, SR, Miller, ML, Monreal, B, Monroe, J, Nickel, BG, Noble, AJ, O'Keeffe, HM, Oblath, NS, Okada, CE, Ollerhead, RW, Gann, GD Orebi, Oser, SM, Ott, RA, Peeters, SJM, Poon, AWP, Prior, G, Reitzner, SD, and Rielage, K

Subjects
hep-ex
Abstract

Neutron production in GeV-scale neutrino interactions is a poorly studiedprocess. We have measured the neutron multiplicities in atmospheric neutrinointeractions in the Sudbury Neutrino Observatory experiment and compared themto the prediction of a Monte Carlo simulation using GENIE and a minimallymodified version of GEANT4. We analyzed 837 days of exposure corresponding toPhase I, using pure heavy water, and Phase II, using a mixture of Cl in heavywater. Neutrons produced in atmospheric neutrino interactions were identifiedwith an efficiency of $15.3\%$ and $44.3\%$, for Phase I and II respectively.The neutron production is measured as a function of the visible energy of theneutrino interaction and, for charged current quasi-elastic interactioncandidates, also as a function of the neutrino energy. This study is alsoperformed classifying the complete sample into two pairs of event categories:charged current quasi-elastic and non charged current quasi-elastic, and$\nu_{\mu}$ and $\nu_e$. Results show good overall agreement between data andMonte Carlo for both phases, with some small tension with a statisticalsignificance below $2\sigma$ for some intermediate energies.

Published
2019

5. In-situ characterization of the Hamamatsu R5912-HQE photomultiplier tubes used in the DEAP-3600 experiment

Author

Amaudruz, P-A, Batygov, M, Beltran, B, Bina, CE, Bishop, D, Bonatt, J, Boorman, G, Boulay, MG, Broerman, B, Bromwich, T, Bueno, JF, Butcher, A, Cai, B, Chan, S, Chen, M, Chouinard, R, Churchwell, S, Cleveland, BT, Cranshaw, D, Dering, K, Dittmeier, S, Duncan, FA, Dunford, M, Erlandson, A, Fatemighomi, N, Ford, RJ, Gagnon, R, Giampa, P, Golovko, VV, Gorel, P, Gornea, R, Grace, E, Graham, K, Grant, DR, Gulyev, E, Hall, A, Hallin, AL, Hamstra, M, Harvey, PJ, Hearns, C, Jillings, CJ, Kamaev, O, Kemp, A, Kuźniak, M, Langrock, S, La Zia, F, Lehnert, B, Li, O, Lidgard, JJ, Liimatainen, P, Lim, C, Lindner, T, Linn, Y, Liu, S, Mathew, R, McDonald, AB, McElroy, T, McFarlane, K, McLaughlin, J, Mead, S, Mehdiyev, R, Mielnichuk, C, Monroe, J, Muir, A, Nadeau, P, Nantais, C, Ng, C, Noble, AJ, O’Dwyer, E, Ohlmann, C, Olchanski, K, Olsen, KS, Ouellet, C, Pasuthip, P, Peeters, SJM, Pollmann, TR, Rand, ET, Rau, W, Rethmeier, C, Retière, F, Seeburn, N, Shaw, B, Singhrao, K, Skensved, P, Smith, B, Smith, NJT, Sonley, T, Stainforth, R, Stone, C, Strickland, V, Sur, B, Tang, J, Taylor, J, Veloce, L, Vázquez-Jáuregui, E, Walding, J, Ward, M, Westerdale, S, White, R, and Woolsey, E

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, PMT, Hamamatsu R5912-HQE, Single photoelectron charge distribution, Afterpulsing, Late and double pulsing, Dark noise, Dark matter detection, physics.ins-det, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Other Physical Sciences, Nuclear & Particles Physics, Nuclear and plasma physics
Abstract

The Hamamatsu R5912-HQE photomultiplier-tube (PMT) is a novel high-quantum efficiency PMT. It is currently used in the DEAP-3600 dark matter detector and is of significant interest for future dark matter and neutrino experiments where high signal yields are needed. We report on the methods developed for in-situ characterization and monitoring of DEAP's 255 R5912-HQE PMTs. This includes a detailed discussion of typical measured single-photoelectron charge distributions, correlated noise (afterpulsing), dark noise, double, and late pulsing characteristics. The characterization is performed during the detector commissioning phase using laser light injected through a light diffusing sphere and during normal detector operation using LED light injected through optical fibres.

Published
2019

6. In-situ characterization of the Hamamatsu R5912-HQE photomultiplier tubes used in the DEAP-3600 experiment

Author

Amaudruz, PA, Batygov, M, Beltran, B, Bina, CE, Bishop, D, Bonatt, J, Boorman, G, Boulay, MG, Broerman, B, Bromwich, T, Bueno, JF, Butcher, A, Cai, B, Chan, S, Chen, M, Chouinard, R, Churchwell, S, Cleveland, BT, Cranshaw, D, Dering, K, Dittmeier, S, Duncan, FA, Dunford, M, Erlandson, A, Fatemighomi, N, Ford, RJ, Gagnon, R, Giampa, P, Golovko, VV, Gorel, P, Gornea, R, Grace, E, Graham, K, Grant, DR, Gulyev, E, Hall, A, Hallin, AL, Hamstra, M, Harvey, PJ, Hearns, C, Jillings, CJ, Kamaev, O, Kemp, A, Kuźniak, M, Langrock, S, La Zia, F, Lehnert, B, Li, O, Lidgard, JJ, Liimatainen, P, Lim, C, Lindner, T, Linn, Y, Liu, S, Mathew, R, McDonald, AB, McElroy, T, McFarlane, K, McLaughlin, J, Mead, S, Mehdiyev, R, Mielnichuk, C, Monroe, J, Muir, A, Nadeau, P, Nantais, C, Ng, C, Noble, AJ, O'Dwyer, E, Ohlmann, C, Olchanski, K, Olsen, KS, Ouellet, C, Pasuthip, P, Peeters, SJM, Pollmann, TR, Rand, ET, Rau, W, Rethmeier, C, Retière, F, Seeburn, N, Shaw, B, Singhrao, K, Skensved, P, Smith, B, Smith, NJT, Sonley, T, Stainforth, R, Stone, C, Strickland, V, Sur, B, Tang, J, Taylor, J, Veloce, L, Vázquez-Jáuregui, E, Walding, J, Ward, M, Westerdale, S, White, R, and Woolsey, E

Subjects
PMT, Hamamatsu R5912-HQE, Single photoelectron charge distribution, Afterpulsing, Late and double pulsing, Dark noise, Dark matter detection, physics.ins-det, Nuclear & Particles Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Other Physical Sciences
Abstract

The Hamamatsu R5912-HQE photomultiplier-tube (PMT) is a novel high-quantum efficiency PMT. It is currently used in the DEAP-3600 dark matter detector and is of significant interest for future dark matter and neutrino experiments where high signal yields are needed. We report on the methods developed for in-situ characterization and monitoring of DEAP's 255 R5912-HQE PMTs. This includes a detailed discussion of typical measured single-photoelectron charge distributions, correlated noise (afterpulsing), dark noise, double, and late pulsing characteristics. The characterization is performed during the detector commissioning phase using laser light injected through a light diffusing sphere and during normal detector operation using LED light injected through optical fibres.

Published
2019

7. Design and construction of the DEAP-3600 dark matter detector

Author

Amaudruz, P-A, Baldwin, M, Batygov, M, Beltran, B, Bina, CE, Bishop, D, Bonatt, J, Boorman, G, Boulay, MG, Broerman, B, Bromwich, T, Bueno, JF, Burghardt, PM, Butcher, A, Cai, B, Chan, S, Chen, M, Chouinard, R, Churchwell, S, Cleveland, BT, Cranshaw, D, Dering, K, DiGioseffo, J, Dittmeier, S, Duncan, FA, Dunford, M, Erlandson, A, Fatemighomi, N, Florian, S, Flower, A, Ford, RJ, Gagnon, R, Giampa, P, Golovko, VV, Gorel, P, Gornea, R, Grace, E, Graham, K, Grant, DR, Gulyev, E, Hall, A, Hallin, AL, Hamstra, M, Harvey, PJ, Hearns, C, Jillings, CJ, Kamaev, O, Kemp, A, Kuźniak, M, Langrock, S, La Zia, F, Lehnert, B, Li, O, Lidgard, JJ, Liimatainen, P, Lim, C, Lindner, T, Linn, Y, Liu, S, Majewski, P, Mathew, R, McDonald, AB, McElroy, T, McFarlane, K, McGinn, T, McLaughlin, JB, Mead, S, Mehdiyev, R, Mielnichuk, C, Monroe, J, Muir, A, Nadeau, P, Nantais, C, Ng, C, Noble, AJ, O’Dwyer, E, Ohlmann, C, Olchanski, K, Olsen, KS, Ouellet, C, Pasuthip, P, Peeters, SJM, Pollmann, TR, Rand, ET, Rau, W, Rethmeier, C, Retière, F, Seeburn, N, Shaw, B, Singhrao, K, Skensved, P, Smith, B, Smith, NJT, Sonley, T, Soukup, J, Stainforth, R, Stone, C, Strickland, V, Sur, B, and Tang, J

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Dark matter, WIMP, Liquid Argon, DEAP, SNOLAB, Low background, astro-ph.IM, hep-ex, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Astronomical sciences, Particle and high energy physics
Abstract

The Dark matter Experiment using Argon Pulse-shape discrimination (DEAP) has been designed for a direct detection search for particle dark matter using a single-phase liquid argon target. The projected cross section sensitivity for DEAP-3600 to the spin-independent scattering of Weakly Interacting Massive Particles (WIMPs) on nucleons is 10−46cm2 for a 100 GeV/c2 WIMP mass with a fiducial exposure of 3 tonne-years. This paper describes the physical properties and construction of the DEAP-3600 detector.

Published
2019

8. Design and construction of the DEAP-3600 dark matter detector

Author

Amaudruz, PA, Baldwin, M, Batygov, M, Beltran, B, Bina, CE, Bishop, D, Bonatt, J, Boorman, G, Boulay, MG, Broerman, B, Bromwich, T, Bueno, JF, Burghardt, PM, Butcher, A, Cai, B, Chan, S, Chen, M, Chouinard, R, Churchwell, S, Cleveland, BT, Cranshaw, D, Dering, K, DiGioseffo, J, Dittmeier, S, Duncan, FA, Dunford, M, Erlandson, A, Fatemighomi, N, Florian, S, Flower, A, Ford, RJ, Gagnon, R, Giampa, P, Golovko, VV, Gorel, P, Gornea, R, Grace, E, Graham, K, Grant, DR, Gulyev, E, Hall, A, Hallin, AL, Hamstra, M, Harvey, PJ, Hearns, C, Jillings, CJ, Kamaev, O, Kemp, A, Kuźniak, M, Langrock, S, La Zia, F, Lehnert, B, Li, O, Lidgard, JJ, Liimatainen, P, Lim, C, Lindner, T, Linn, Y, Liu, S, Majewski, P, Mathew, R, McDonald, AB, McElroy, T, McFarlane, K, McGinn, T, McLaughlin, JB, Mead, S, Mehdiyev, R, Mielnichuk, C, Monroe, J, Muir, A, Nadeau, P, Nantais, C, Ng, C, Noble, AJ, O'Dwyer, E, Ohlmann, C, Olchanski, K, Olsen, KS, Ouellet, C, Pasuthip, P, Peeters, SJM, Pollmann, TR, Rand, ET, Rau, W, Rethmeier, C, Retière, F, Seeburn, N, Shaw, B, Singhrao, K, Skensved, P, Smith, B, Smith, NJT, Sonley, T, Soukup, J, Stainforth, R, Stone, C, Strickland, V, Sur, B, and Tang, J

Subjects
Dark matter, WIMP, Liquid Argon, DEAP, SNOLAB, Low background, astro-ph.IM, hep-ex, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics
Abstract

The Dark matter Experiment using Argon Pulse-shape discrimination (DEAP) has been designed for a direct detection search for particle dark matter using a single-phase liquid argon target. The projected cross section sensitivity for DEAP-3600 to the spin-independent scattering of Weakly Interacting Massive Particles (WIMPs) on nucleons is 10−46cm2 for a 100 GeV/c2 WIMP mass with a fiducial exposure of 3 tonne-years. This paper describes the physical properties and construction of the DEAP-3600 detector.

Published
2019

9. Constraints on neutrino lifetime from the Sudbury Neutrino Observatory

Author

Aharmim, B, Ahmed, SN, Anthony, AE, Barros, N, Beier, EW, Bellerive, A, Beltran, B, Bergevin, M, Biller, SD, Bonventre, R, Boudjemline, K, Boulay, MG, Cai, B, Callaghan, EJ, Caravaca, J, Chan, YD, Chauhan, D, Chen, M, Cleveland, BT, Cox, GA, Dai, X, Deng, H, Descamps, FB, Detwiler, JA, Doe, PJ, Doucas, G, Drouin, P-L, Dunford, M, Elliott, SR, Evans, HC, Ewan, GT, Farine, J, Fergani, H, Fleurot, F, Ford, RJ, Formaggio, JA, Gagnon, N, Gilje, K, Goon, J TM, Graham, K, Guillian, E, Habib, S, Hahn, RL, Hallin, AL, Hallman, ED, Harvey, PJ, Hazama, R, Heintzelman, WJ, Heise, J, Helmer, RL, Hime, A, Howard, C, Huang, M, Jagam, P, Jamieson, B, Jelley, NA, Jerkins, M, Kéfélian, C, Keeter, KJ, Klein, JR, Kormos, LL, Kos, M, Krüger, A, Kraus, C, Krauss, CB, Kutter, T, Kyba, CCM, Land, BJ, Lange, R, Law, J, Lawson, IT, Lesko, KT, Leslie, JR, Levine, I, Loach, JC, MacLellan, R, Majerus, S, Mak, HB, Maneira, J, Martin, RD, Mastbaum, A, McCauley, N, McDonald, AB, McGee, SR, Miller, ML, Monreal, B, Monroe, J, Nickel, BG, Noble, AJ, O’Keeffe, HM, Oblath, NS, Okada, CE, Ollerhead, RW, Gann, GD Orebi, Oser, SM, Ott, RA, Peeters, SJM, Poon, AWP, Prior, G, and Reitzner, SD

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, hep-ex, nucl-ex
Abstract

The long baseline between Earth and the Sun makes solar neutrinos an excellent test beam for exploring possible neutrino decay. The signature of such decay would be an energy-dependent distortion of the traditional survival probability which can be fit for using well-developed and high-precision analysis methods. Here a model including neutrino decay is fit to all three phases of B8 solar neutrino data taken by the Sudbury Neutrino Observatory (SNO). This fit constrains the lifetime of neutrino mass state ν2 to be >8.08×10-5 s/eV at 90% confidence. An analysis combining this SNO result with those from other solar neutrino experiments results in a combined limit for the lifetime of mass state ν2 of >1.92×10-3 s/eV at 90% confidence.

Published
2019

10. Tests of Lorentz invariance at the Sudbury Neutrino Observatory

Author

Aharmim, B, Ahmed, SN, Anthony, AE, Barros, N, Beier, EW, Bellerive, A, Beltran, B, Bergevin, M, Biller, SD, Blucher, E, Bonventre, R, Boudjemline, K, Boulay, MG, Cai, B, Callaghan, EJ, Caravaca, J, Chan, YD, Chauhan, D, Chen, M, Cleveland, BT, Cox, GA, Dai, X, Deng, H, Descamps, FB, Detwiler, JA, Doe, PJ, Doucas, G, Drouin, P-L, Dunford, M, Elliott, SR, Evans, HC, Ewan, GT, Farine, J, Fergani, H, Fleurot, F, Ford, RJ, Formaggio, JA, Gagnon, N, Gilje, K, Goon, J TM, Graham, K, Guillian, E, Habib, S, Hahn, RL, Hallin, AL, Hallman, ED, Harvey, PJ, Hazama, R, Heintzelman, WJ, Heise, J, Helmer, RL, Hime, A, Howard, C, Huang, M, Jagam, P, Jamieson, B, Jelley, NA, Jerkins, M, Kéfélian, C, Keeter, KJ, Klein, JR, Kormos, LL, Kos, M, Krüger, A, Kraus, C, Krauss, CB, Kutter, T, Kyba, CCM, Labe, K, Land, BJ, Lange, R, LaTorre, A, Law, J, Lawson, IT, Lesko, KT, Leslie, JR, Levine, I, Loach, JC, MacLellan, R, Majerus, S, Mak, HB, Maneira, J, Martin, RD, Mastbaum, A, McCauley, N, McDonald, AB, McGee, SR, Miller, ML, Monreal, B, Monroe, J, Nickel, BG, Noble, AJ, O’Keeffe, HM, Oblath, NS, Okada, CE, Ollerhead, RW, Gann, GD Orebi, Oser, SM, Ott, RA, and Peeters, SJM

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, hep-ex, nucl-ex
Abstract

Experimental tests of Lorentz symmetry in systems of all types are critical for ensuring that the basic assumptions of physics are well founded. Data from all phases of the Sudbury Neutrino Observatory, a kiloton-scale heavy water Cherenkov detector, are analyzed for possible violations of Lorentz symmetry in the neutrino sector. Such violations would appear as one of eight possible signal types in the detector: six seasonal variations in the solar electron neutrino survival probability differing in energy and time dependence and two shape changes to the oscillated solar neutrino energy spectrum. No evidence for such signals is observed, and limits on the size of such effects are established in the framework of the standard model extension, including 38 limits on previously unconstrained operators and improved limits on 16 additional operators. This makes limits on all minimal, Dirac-type Lorentz violating operators in the neutrino sector available for the first time.

Published
2018

11. Search for neutron-Antineutron oscillations at the Sudbury Neutrino Observatory

Author

Aharmim, B, Ahmed, SN, Anthony, AE, Barros, N, Beier, EW, Bellerive, A, Beltran, B, Bergevin, M, Biller, SD, Boudjemline, K, Boulay, MG, Cai, B, Chan, YD, Chauhan, D, Chen, M, Cleveland, BT, Cox, GA, Dai, X, Deng, H, Detwiler, JA, Doe, PJ, Doucas, G, Drouin, PL, Duncan, FA, Dunford, M, Earle, ED, Elliott, SR, Evans, HC, Ewan, GT, Farine, J, Fergani, H, Fleurot, F, Ford, RJ, Formaggio, JA, Gagnon, N, Goon, JT, Graham, K, Guillian, E, Habib, S, Hahn, RL, Hallin, AL, Hallman, ED, Harvey, PJ, Hazama, R, Heintzelman, WJ, Heise, J, Helmer, RL, Hime, A, Howard, C, Huang, M, Jagam, P, Jamieson, B, Jelley, NA, Jerkins, M, Keeter, KJ, Klein, JR, Kormos, LL, Kos, M, Krüger, A, Kraus, C, Krauss, CB, Kutter, T, Kyba, CCM, Lange, R, Law, J, Lawson, IT, Lesko, KT, Leslie, JR, Levine, I, Loach, JC, Maclellan, R, Majerus, S, Mak, HB, Maneira, J, Martin, RD, McCauley, N, McDonald, AB, McGee, SR, Miller, ML, Monreal, B, Monroe, J, Nickel, BG, Noble, AJ, O'Keeffe, HM, Oblath, NS, Okada, CE, Ollerhead, RW, Orebi Gann, GD, Oser, SM, Ott, RA, Peeters, SJM, Poon, AWP, Prior, G, Reitzner, SD, Rielage, K, Robertson, BC, Robertson, RGH, Schwendener, MH, Secrest, JA, and Seibert, SR

Subjects
hep-ex, nucl-ex, physics.ins-det
Abstract

Tests on B-L symmetry breaking models are important probes to search for new physics. One proposed model with Δ(B-L)=2 involves the oscillations of a neutron to an antineutron. In this paper, a new limit on this process is derived for the data acquired from all three operational phases of the Sudbury Neutrino Observatory experiment. The search concentrated on oscillations occurring within the deuteron, and 23 events were observed against a background expectation of 30.5 events. These translated to a lower limit on the nuclear lifetime of 1.48×1031 yr at 90% C.L. when no restriction was placed on the signal likelihood space (unbounded). Alternatively, a lower limit on the nuclear lifetime was found to be 1.18×1031 yr at 90% C.L. when the signal was forced into a positive likelihood space (bounded). Values for the free oscillation time derived from various models are also provided in this article. This is the first search for neutron-Antineutron oscillation with the deuteron as a target.

Published
2017

12. Direct comparison of PEN and TPB wavelength shifters in a liquid argon detector

Author

Boulay, Mg, Camillo, V, Canci, N, Choudhary, S, Consiglio, L, Flammini, A, Galbiati, C, Ghiano, C, Gola, A, Horikawa, S, Kachru, P, Kochanek, I, Kondo, K, Korga, G, Kuzniak, M, Kuzwa, M, Leonhardt, A, Lecki, T, Mazzi, A, Moharana, A, Nieradka, G, Paternoster, G, Pollmann, Tr, Razeto, A, Sablone, D, Sworobowicz, T, Szelc, Am, Turkoglu, C, and Wang, H

Subjects
QB460-466, Physics - Instrumentation and Detectors, Physics and Astronomy (miscellaneous), Physics::Instrumentation and Detectors, Nuclear and particle physics. Atomic energy. Radioactivity, Physics::Atomic and Molecular Clusters, FOS: Physical sciences, QC770-798, Instrumentation and Detectors (physics.ins-det), Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Engineering (miscellaneous)
Abstract

A large number of particle detectors employ liquid argon as their target material owing to its high scintillation yield and its ability to drift ionization charge over large distances. Scintillation light from argon is peaked at 128 nm and a wavelength shifter is required for its efficient detection. In this work, we directly compare the light yield achieved in two identical liquid argon chambers, one of which is equipped with PolyEthylene Naphthalate (PEN) and the other with TetraPhenyl Butadiene (TPB) wavelength shifter. Both chambers are lined with enhanced specular reflectors and instrumented with SiPMs with a coverage fraction of approximately 1%, which represents a geometry comparable to the future large scale detectors. We measured the light yield of the PEN chamber to be 39.4$\pm$0.4(stat)$\pm$1.9(syst)% of the yield of the TPB chamber. Using a Monte Carlo simulation this result is used to extract the wavelength shifting efficiency of PEN relative to TPB equal to 47.2$\pm$5.7%. This result paves the way for the use of easily available PEN foils as a wavelength shifter, which can substantially simplify the construction of future liquid argon detectors., Comment: 7 pages, 7 figures

Published
2021

13. Measurement of the $ν_e$ and Total $^{8}$B Solar Neutrino Fluxes with the Sudbury Neutrino Observatory Phase-III Data Set

Author

Aharmim, B, Ahmed, SN, Amsbaugh, J, Anaya, J, Anthony, A, Banar, J, Barros, N, Beier, E, Bellerive, A, Beltran, B, Bergevin, M, Biller, S, Boudjemline, K, Boulay, MG, Bowles, T, Browne, M, Bullard, T, Burritt, T, Cai, B, Chan, Y, Chauhan, D, Chen, M, Cleveland, B, Cox, G, and Currat, C

Abstract

This paper details the solar neutrino analysis of the 385.17-day Phase-III data set acquired by the Sudbury Neutrino Observatory (SNO). An array of $^3$He proportional counters was installed in the heavy-water target to measure precisely the rate of neutrino-deuteron neutral-current interactions. This technique to determine the total active $^8$B solar neutrino flux was largely independent of the methods employed in previous phases. The total flux of active neutrinos was measured to be $5.54^{+0.33}_{-0.31}(stat.)^{+0.36}_{-0.34}(syst.)\times 10^{6}$ cm$^{-2}$ s$^{-1}$, consistent with previous measurements and standard solar models. A global analysis of solar and reactor neutrino mixing parameters yielded the best-fit values of $\Delta m^2 = 7.59^{+0.19}_{-0.21}\times 10^{-5}{eV}^2$ and $\theta = 34.4^{+1.3}_{-1.2}$ degrees.

Published
2016

14. Measurement of the rate of ve + d → p + p + e- interactions produced by 8B solar neutrinos at the sudbury neutrino observatory

Author

Ahmad, Q, Allen, R, Andersen, T, Anglin, J, Bühler, G, Barton, J, Beier, E, Bercovitch, M, Bigu, J, Biller, S, Black, R, Blevis, I, Bardman, R, Boger, J, Bonvin, E, Boulay, MG, Bowler, MG, Bowles, T, Brice, S, Browne, M, Bullard, T, Burritt, T, Cameron, K, Cameron, J, and Chan, Y

Abstract

The 8B flux from elastic scattering (ES) and charged current (CC) of electrons was recorded at the Sudbury Neutrino Observatory (SNO) between November 2, 1999 and January 15, 2001. Data were partitioned into two sets then analyzed. As a result, the first direct indication of a nonelectron flavor component in the solar neutrino flux was established.

Published
2016

15. Search for periodicities in the B-8 solar neutrino flux measured by the Sudbury Neutrino Observatory

Author

Aharmim, B, Ahmed, SN, Anthony, A, Beier, E, Bellerive, A, Bergevin, M, Biller, S, Boulay, MG, Bowler, MG, Chan, Y, Chen, M, Chen, X, Cleveland, B, Costin, T, Cox, G, Currat, C, Dai, X, Deng, H, Detwiler, J, Doe, P, Dosanjh, R, Doucas, G, Duba, C, Duncan, F, and Dunford, M

Abstract

A search has been made for sinusoidal periodic variations in the B8 solar neutrino flux using data collected by the Sudbury Neutrino Observatory over a 4-year time interval. The variation at a period of 1 yr is consistent with modulation of the B8 neutrino flux by the Earth's orbital eccentricity. No significant sinusoidal periodicities are found with periods between 1 d and 10 years with either an unbinned maximum likelihood analysis or a Lomb-Scargle periodogram analysis. The data are inconsistent with the hypothesis that the results of the recent analysis by Sturrock et al., based on elastic scattering events in Super-Kamiokande, can be attributed to a 7% sinusoidal modulation of the total B8 neutrino flux. © 2005 The American Physical Society.

Published
2016

16. Determination of the νe and total B8 solar neutrino fluxes using the Sudbury Neutrino Observatory Phase I data set

Author

Aharmim, B, Ahmad, Q, Ahmed, SN, Allen, R, Andersen, T, Anglin, J, Bühler, G, Barton, J, Beier, E, Bercovitch, M, Bergevin, M, Bigu, J, Biller, S, Black, R, Blevis, I, Boardman, R, Boger, J, Bonvin, E, Boulay, MG, Bowler, MG, Bowles, T, Brice, S, Browne, M, Bullard, T, and Burritt, T

Abstract

This article provides the complete description of results from the Phase I data set of the Sudbury Neutrino Observatory (SNO). The Phase I data set is based on a 0.65 kiloton-year exposure of 2H2O (in the following denoted as D2O) to the solar B8 neutrino flux. Included here are details of the SNO physics and detector model, evaluations of systematic uncertainties, and estimates of backgrounds. Also discussed are SNO's approach to statistical extraction of the signals from the three neutrino reactions (charged current, neutral current, and elastic scattering) and the results of a search for a day-night asymmetry in the νe flux. Under the assumption that the B8 spectrum is undistorted, the measurements from this phase yield a solar νe flux of (νe)=1.76-0.05+0. 05(stat.)-0.09+0.09(syst.)×106 cm-2 s-1 and a non-νe component of (νμτ)=3.41-0.45+0.45(stat.)-0.45+0.48(syst.)×106 cm-2 s-1. The sum of these components provides a total flux in excellent agreement with the predictions of standard solar models. The day-night asymmetry in the νe flux is found to be Ae=7.0±4.9(stat.)-1.2+1.3%(syst.), when the asymmetry in the total flux is constrained to be zero. © 2007 The American Physical Society.

Published
2016

18. Measurement of the total active 8B solar neutrino flux at the Sudbury Neutrino Observatory with enhanced neutral current sensitivity

Author

Ahmed, SN, Anthony, A, Beier, E, Bellerive, A, Biller, S, Boger, J, Boulay, MG, Bowler, MG, Bowles, T, Brice, S, Bullard, T, Chan, Y, Chen, M, Chen, X, Cleveland, B, Cox, G, Dai, X, Dalnoki-Veress, F, Doe, P, Dosanjh, R, Doucas, G, Dragowsky, MR, Duba, C, Duncan, F, and Dunford, M

Abstract

The Sudbury Neutrino Observatory has precisely determined the total active (nu(x)) 8B solar neutrino flux without assumptions about the energy dependence of the nu(e) survival probability. The measurements were made with dissolved NaCl in heavy water to enhance the sensitivity and signature for neutral-current interactions. The flux is found to be 5.21 +/- 0.27(stat)+/-0.38(syst) x 10(6) cm(-2) s(-1), in agreement with previous measurements and standard solar models. A global analysis of these and other solar and reactor neutrino results yields Deltam(2)=7.1(+1.2)(-0.6) x 10(-5) eV(2) and theta=32.5(+2.4)(-2.3) degrees. Maximal mixing is rejected at the equivalent of 5.4 standard deviations.

Published
2016

19. Independent measurement of the total active 8B solar neutrino flux using an array of 3He proportional counters at the Sudbury Neutrino Observatory

Author

Aharmim, B, Ahmed, SN, Amsbaugh, J, Anthony, A, Banar, J, Barros, N, Beier, E, Bellerive, A, Beltran, B, Bergevin, M, Biller, S, Boudjemline, K, Boulay, MG, Bowles, T, Browne, M, Bullard, T, Burritt, T, Cai, B, Chan, Y, Chauhan, D, Chen, M, Cleveland, B, Cox-Mobrand, G, Currat, C, and Dai, X

Abstract

The Sudbury Neutrino Observatory (SNO) used an array of 3He proportional counters to measure the rate of neutral-current interactions in heavy water and precisely determined the total active (nu_x) 8B solar neutrino flux. This technique is independent of previous methods employed by SNO. The total flux is found to be 5.54_-0.31;+0.33(stat)-0.34+0.36(syst)x10(6) cm(-2) s(-1), in agreement with previous measurements and standard solar models. A global analysis of solar and reactor neutrino results yields Deltam2=7.59_-0.21;+0.19x10(-5) eV2 and theta=34.4_-1.2;+1.3 degrees. The uncertainty on the mixing angle has been reduced from SNO's previous results.

Published
2016

20. Electron energy spectra, fluxes, and day-night asymmetries of B-8 solar neutrinos from measurements with NaCl dissolved in the heavy-water detector at the Sudbury Neutrino Observatory

Author

Aharmim, B, Ahmed, SN, Anthony, A, Beier, E, Bellerive, A, Bergevin, M, Biller, S, Boger, J, Boulay, MG, Bowler, MG, Bullard, T, Chan, Y, Chen, M, Chen, X, Cleveland, B, Cox, G, Currat, C, Dai, X, Dalnoki-Veress, F, Deng, H, Doe, P, Dosanjh, R, Doucas, G, Duba, C, and Duncan, F

Abstract

Results are reported from the complete salt phase of the Sudbury Neutrino Observatory experiment in which NaCl was dissolved in the H22O ("D2O") target. The addition of salt enhanced the signal from neutron capture as compared to the pure D2O detector. By making a statistical separation of charged-current events from other types based on event-isotropy criteria, the effective electron recoil energy spectrum has been extracted. In units of 106cm-2s-1, the total flux of active-flavor neutrinos from B8 decay in the Sun is found to be 4.94-0.21+0.21(stat)-0.34+0.38(syst) and the integral flux of electron neutrinos for an undistorted B8 spectrum is 1.68-0.06+0.06(stat)-0. 09+0.08(syst); the signal from (νx,e) elastic scattering is equivalent to an electron-neutrino flux of 2.35-0.22+0.22(stat)-0.15+0.15(syst). These results are consistent with those expected for neutrino oscillations with the so-called large mixing angle parameters and also with an undistorted spectrum. A search for matter-enhancement effects in the Earth through a possible day-night asymmetry in the charged-current integral rate is consistent with no asymmetry. Including results from other experiments, the best-fit values for two-neutrino mixing parameters are Δm2=(8.0-0.4+0.6)×10-5 eV2 and θ=33.9-2.2+2.4 degrees. © 2005 The American Physical Society.

Published
2016

21. Recent Results from SNO

Author

Sinclair, D, Kutter, T, Nally, CW, Oser, SM, Waltham, CE, Boger, J, Hahn, RL, Lange, R, Yeh, M, Bellerive, A, Dai, X, Dalnoki-Veress, F, Dosanjh, RS, Grant, DR, Hargrove, CK, Hemingway, RJ, Levine, I, Mifflin, C, Rollin, E, Simard, O, Starinsky, N, Tesic, G, Waller, D, Jagam, P, Labranche, H, Law, J, Lawson, IT, Nickel, BG, Ollerhead, RW, Simpson, JJ, Farine, J, Fleurot, F, Hallman, ED, Luoma, S, Schwendener, MH, Tafirout, R, Virtue, CJ, Chan, YD, Chen, X, Heeger, KM, Lesko, KT, Marino, AD, Norman, EB, Okada, CE, Poon, AWP, Rosendahl, SSE, Stokstad, RG, Boulay, MG, Bowles, TJ, Brice, SJ, Dragowsky, MR, Elliott, SR, Fowler, MM, Hamer, AS, Heise, J, Hime, A, Miller, GG, Van de Water, RG, Wilhelmy, JB, Wouters, JM, Biller, SD, Bowler, MG, Cleveland, BT, Doucas, G, Dunmore, JA, Fergani, H, Frame, K, Jelley, NA, Majerus, S, McGregor, G, Peeters, SJM, Sims, CJ, Thorman, M, Tseung, HWC, West, N, Wilson, JR, Zuber, K, Beier, EW, Dunford, M, Heintzelman, WJ, Kyba, CCM, McCauley, N, Rusu, VL, Van Berg, R, Ahmed, SN, Chen, M, Duncan, FA, Earle, ED, Fulsom, BG, Evans, HC, Ewan, GT, Graham, K, Hallin, AL, Handler, WB, Harvey, PJ, Kos, MS, Krumins, AV, Leslie, JR, and MacLellan, R

Subjects
Heavy water, chemistry.chemical_classification, Nuclear and High Energy Physics, chemistry.chemical_compound, Materials science, chemistry, Seesaw molecular geometry, Chemical engineering, Phase (matter), Salt (chemistry), Nanotechnology, Atomic and Molecular Physics, and Optics
Abstract

The SNO project has now completed two of its three major phases of operation. The no-oscillation hypothesis has been ruled out at 5σ in the pure heavy water phase and 8σ in the salt phase. Discussion in terms of the SeeSaw model is presented. © 2004 Published by Elsevier B.V.

Published
2004

22. Measurement of the scintillation time spectra and pulse-shape discrimination of low-energy beta and nuclear recoils in liquid argon with DEAP-1

Author

Boulay, MG, Cai, B, Chen, M, Golovko, V, Harvey, P, Mathew, R, Lidgard, J, McDonald, AB, Pasuthip, P, Pollman, T, Skensved, P, Graham, K, Hallin, A, McKinsey, D, Lippincott, W, Nikkel, J, Jillings, C, Duncan, F, Cleveland, B, and Lawson, I

Subjects
Physics::Instrumentation and Detectors, Nuclear Experiment
Abstract

The DEAP-1 low-background liquid argon detector has been used to measure scintillation pulse shapes of beta decays and nuclear recoil events and to demonstrate the feasibility of pulse-shape discrimination down to an electron-equivalent energy of 20 keVee. The relative intensities of singlet/triplet states in liquid argon have been measured as a function of energy between 15 and 500 keVee for both beta and nuclear recoils. Using a triple-coincidence tag we find the fraction of beta events that are mis-identified as nuclear recoils to be less than 6x10^{-8} between 43-86 keVee and that the discrimination parameter agrees with a simple analytic model. The discrimination measurement is currently limited by nuclear recoils induced by cosmic-ray generated neutrons, and is expected to improve by operating the detector underground at SNOLAB. The analytic model predicts a beta mis-identification fraction of 10^{-10} for an electron-equivalent energy threshold of 20 keVee. This reduction allows for a sensitive search for spin-independent scattering of WIMPs from 1000 kg of liquid argon with a WIMP-nucleon cross-section sensitivity of 10^{-46} cm^{2}.

Published
2009

23. Determination of the nu(e) and total B-8 solar neutrino fluxes using the Sudbury Neutrino Observatory Phase I data set

Author

Aharmim, B, Ahmad, QR, Ahmed, SN, Allen, RC, Andersen, TC, Anglin, JD, Buehler, G, Barton, JC, Beier, EW, Bercovitch, M, Bergevin, M, Bigu, J, Biller, SD, Black, RA, Blevis, I, Boardman, RJ, Boger, J, Bonvin, E, Boulay, MG, Bowler, MG, Bowles, TJ, Brice, SJ, Browne, MC, Bullard, TV, Burritt, TH, Cameron, J, Chan, YD, Chen, HH, Chen, M, Chen, X, Cleveland, BT, Cowan, JHM, Cowen, DF, Cox, GA, Currat, CA, Dai, X, Dalnoki-Veress, F, Davidson, WF, Deng, H, DiMarco, M, Doe, PJ, Doucas, G, Dragowsky, MR, Duba, CA, Duncan, FA, Dunford, M, Dunmore, JA, Earle, ED, Elliott, SR, Evans, HC, Ewan, GT, Farine, J, Fergani, H, Ferraris, AP, Fleurot, F, Ford, RJ, Formaggio, JA, Fowler, MM, Frame, K, Frank, ED, Frati, W, Gagnon, N, Germani, JV, Gil, S, Goldschmidt, A, Goon, JTM, Graham, K, Grant, DR, Guillian, E, Hahn, RL, Hallin, AL, Hallman, ED, Hamer, AS, Hamian, AA, Handler, WB, Haq, RU, Hargrove, CK, Harvey, PJ, Hazama, R, Heeger, KM, Heintzelman, WJ, Heise, J, Helmer, RL, Henning, R, Hepburn, JD, Heron, H, Hewett, J, Hime, A, Howard, C, Howe, MA, Huang, M, Hykaway, JG, Isaac, MCP, Jagam, P, Jamieson, B, Jelley, NA, Jillings, C, Jonkmans, G, Kazkaz, K, Keener, PT, Kirch, K, Klein, JR, Knox, AB, Komar, RJ, Kormos, LL, Kos, M, Kouzes, R, Krueger, A, Kraus, C, Krauss, CB, Kutter, T, Kyba, CCM, Labranche, H, Lange, R, Law, J, Lawson, IT, Lay, M, Lee, HW, Lesko, KT, Leslie, JR, Levine, I, Loach, JC, Locke, W, Luoma, S, Lyon, J, MacLellan, R, Majerus, S, Mak, HB, Maneira, J, Marino, AD, Martin, R, McCauley, N, McDonald, AB, McDonald, DS, McFarlane, K, McGee, S, McGregor, G, Drees, RM, Mes, H, Mifflin, C, Miknaitis, KKS, Miller, ML, Milton, G, Moffat, BA, Monreal, B, Moorhead, M, Morrissette, B, Nally, CW, Neubauer, MS, Newcomer, FM, Ng, HS, Nickel, BG, Noble, AJ, Norman, EB, Novikov, VM, Oblath, NS, Okada, CE, O'Keeffe, HM, Ollerhead, RW, Omori, M, Orrell, JL, Oser, SM, Ott, R, Peeters, SJM, Poon, AWP, Prior, G, Reitzner, SD, Rielage, K, Roberge, A, Robertson, BC, Robertson, RGH, Rosendahl, SSE, Rowley, JK, Rusu, VL, Saettler, E, Schulke, A, Schwendener, MH, Secrest, JA, Seifert, H, Shatkay, M, Simpson, JJ, Sims, CJ, Sinclair, D, Skensved, P, Smith, AR, Smith, MWE, Starinsky, N, Steiger, TD, Stokstad, RG, Stonehill, LC, Storey, RS, Sur, B, Tafirout, R, Tagg, N, Takeuchi, Y, Tanner, NW, Taplin, RK, Thorman, M, Thornewell, PM, Tolich, N, Trent, PT, Tserkovnyak, YI, Tsui, T, Tunnell, CD, Van Berg, R, De Water, RGV, Virtue, CJ, Walker, TJ, Wall, BL, Waltham, CE, Tseung, HWC, Wang, J-X, Wark, DL, Wendland, J, West, N, Wilhelmy, JB, Wilkerson, JF, Wilson, JR, Wittich, P, Wouters, JM, Wright, A, Yeh, M, Zuber, K, and Collaboration, SNO

Published
2007

24. Electron energy spectra, fluxes, and day-night asymmetries of B-8 solar neutrinos from measurements with NaCl dissolved in the heavy-water detector at the Sudbury Neutrino Observatory

Author

Aharmim, B, Ahmed, SN, Anthony, AE, Beier, EW, Bellerive, A, Bergevin, M, Biller, SD, Boger, J, Boulay, MG, Bowler, MG, Bullard, TV, Chan, YD, Chen, M, Chen, X, Cleveland, BT, Cox, GA, Currat, CA, Dai, X, Dalnoki-Veress, F, Deng, H, Doe, PJ, Dosanjh, RS, Doucas, G, Duba, CA, Duncan, FA, Dunford, M, Dunmore, JA, Earle, ED, Elliott, SR, Evans, HC, Ewan, GT, Farine, J, Fergani, H, Fleurot, F, Formaggio, JA, Frame, K, Frati, W, Fulsom, BG, Gagnon, N, Graham, K, Grant, DR, Hahn, RL, Hall, JC, Hallin, AL, Hallman, ED, Handler, WB, Hargrove, CK, Harvey, PJ, Hazama, R, Heeger, KM, Heelan, L, Heintzelman, WJ, Heise, J, Helmer, RL, Hemingway, RJ, Hime, A, Howard, C, Howe, MA, Huang, M, Jagam, P, Jelley, NA, Klein, JR, Kormos, LL, Kos, MS, Kruger, A, Kraus, C, Krauss, CB, Krumins, AV, Kutter, T, Kyba, CCM, Labranche, H, Lange, R, Law, J, Lawson, IT, Lesko, KT, Leslie, JR, Levine, I, Loach, JC, Luoma, S, MacLellan, R, Majerus, S, Mak, HB, Maneira, J, Marino, AD, McCauley, N, McDonald, AB, McGee, S, McGregor, G, Mifflin, C, Miknaitis, KKS, Moffat, BA, Nally, CW, Neubauer, MS, Nickel, BG, Noble, AJ, Norman, EB, Oblath, NS, Okada, CE, Ollerhead, RW, Orrell, JL, Oser, SM, Ouellet, C, Peeters, SJM, Poon, AWP, Rielage, K, Robertson, BC, Robertson, RGH, Rollin, E, Rosendahl, SSE, Rusu, VL, Schwendener, MH, Seibert, SR, Simard, O, Simpson, JJ, Sims, CJ, Sinclair, D, Skensved, P, Smith, MWE, Starinsky, N, Stokstad, RG, Stonehill, LC, Tafirout, R, Takeuchi, Y, Tesic, G, Thomson, M, Thorman, M, Tsui, T, Van Berg, R, Van de Water, RG, Virtue, CJ, Wall, BL, Waller, D, Waltham, CE, Tseung, HWC, Wark, DL, Wendland, J, West, N, Wilkerson, JF, Wilson, JR, Wittich, P, Wouters, JM, Wright, A, Yeh, M, Zuber, K, and Collaboration, SNO

Subjects
High Energy Physics::Experiment, Astrophysics::Cosmology and Extragalactic Astrophysics, Nuclear Experiment
Abstract

Results are reported from the complete salt phase of the Sudbury Neutrino Observatory experiment in which NaCl was dissolved in the H22O ("D2O") target. The addition of salt enhanced the signal from neutron capture as compared to the pure D2O detector. By making a statistical separation of charged-current events from other types based on event-isotropy criteria, the effective electron recoil energy spectrum has been extracted. In units of 106cm-2s-1, the total flux of active-flavor neutrinos from B8 decay in the Sun is found to be 4.94-0.21+0.21(stat)-0.34+0.38(syst) and the integral flux of electron neutrinos for an undistorted B8 spectrum is 1.68-0.06+0.06(stat)-0. 09+0.08(syst); the signal from (νx,e) elastic scattering is equivalent to an electron-neutrino flux of 2.35-0.22+0.22(stat)-0.15+0.15(syst). These results are consistent with those expected for neutrino oscillations with the so-called large mixing angle parameters and also with an undistorted spectrum. A search for matter-enhancement effects in the Earth through a possible day-night asymmetry in the charged-current integral rate is consistent with no asymmetry. Including results from other experiments, the best-fit values for two-neutrino mixing parameters are Δm2=(8.0-0.4+0.6)×10-5 eV2 and θ=33.9-2.2+2.4 degrees. © 2005 The American Physical Society.

Published
2005

25. Search for periodicities in the B8 solar neutrino flux measured by the Sudbury Neutrino Observatory

Author

Aharmim, B, Ahmed, SN, Anthony, AE, Beier, EW, Bellerive, A, Bergevin, M, Biller, SD, Boulay, MG, Bowler, MG, Chan, YD, Chen, M, Chen, X, Cleveland, BT, Costin, T, Cox, GA, Currat, CA, Dai, X, Deng, H, Detwiler, J, Doe, PJ, Dosanjh, RS, Doucas, G, Duba, CA, Duncan, FA, Dunford, M, Dunmore, JA, Earle, ED, Elliott, SR, Evans, HC, Ewan, GT, Farine, J, Fergani, H, Fleurot, F, Formaggio, JA, Frati, W, Fulsom, BG, Gagnon, N, Goon, JTM, Graham, K, Hahn, RL, Hallin, AL, Hallman, ED, Handler, WB, Hargrove, CK, Harvey, PJ, Hazama, R, Heeger, KM, Heelan, L, Heintzelman, WJ, Heise, J, Helmer, RL, Hemingway, RJ, Hime, A, Howe, MA, Huang, M, Inrig, E, Jagam, P, Jelley, NA, Klein, JR, Kormos, LL, Kos, MS, Krüger, A, Kraus, C, Krauss, CB, Krumins, AV, Kutter, T, Kyba, CCM, Labranche, H, Lange, R, Law, J, Lawson, IT, Lesko, KT, Leslie, JR, Levine, I, Loach, JC, Luoma, S, MacLellan, R, Majerus, S, Maneira, J, Marino, AD, McCauley, N, McDonald, AB, McGee, S, Mifflin, C, Miknaitis, KKS, Nickel, BG, Noble, AJ, Norman, EB, Oblath, NS, Okada, CE, O'Keeffe, HM, Ollerhead, RW, Gann, GDO, Orrell, JL, Oser, SM, Ouvarova, T, Peeters, SJM, Poon, AWP, Pun, CSJ, Rielage, K, Robertson, BC, Robertson, RGH, Rollin, E, Rosendahl, SSE, Schwendener, MH, Seibert, SR, Simard, O, Simpson, JJ, Sims, CJ, Sinclair, D, Sinclair, L, Skensved, P, Smith, MWE, Stokstad, RG, Stonehill, LC, Tafirout, R, Takeuchi, Y, Tešić, G, Thomson, M, Tsang, KV, Tsui, T, Berg, RV, Virtue, CJ, Wall, BL, Waller, D, Waltham, CE, Tseung, HWC, Wark, DL, Wendland, J, West, N, Wilkerson, JF, Wilson, JR, Wouters, JM, Yeh, M, and Zuber, K

Subjects
Astrophysics::High Energy Astrophysical Phenomena, High Energy Physics::Experiment
Abstract

A search has been made for sinusoidal periodic variations in the B8 solar neutrino flux using data collected by the Sudbury Neutrino Observatory over a 4-year time interval. The variation at a period of 1 yr is consistent with modulation of the B8 neutrino flux by the Earth's orbital eccentricity. No significant sinusoidal periodicities are found with periods between 1 d and 10 years with either an unbinned maximum likelihood analysis or a Lomb-Scargle periodogram analysis. The data are inconsistent with the hypothesis that the results of the recent analysis by Sturrock et al., based on elastic scattering events in Super-Kamiokande, can be attributed to a 7% sinusoidal modulation of the total B8 neutrino flux. © 2005 The American Physical Society.

Published
2005

26. Search for periodicities in the B-8 solar neutrino flux measured by the Sudbury Neutrino Observatory

Author

Aharmim, B, Ahmed, SN, Anthony, AE, Beier, EW, Bellerive, A, Bergevin, M, Biller, SD, Boulay, MG, Bowler, MG, Chan, YD, Chen, M, Chen, X, Cleveland, BT, Costin, T, Cox, GA, Currat, CA, Dai, X, Deng, H, Detwiler, J, Doe, PJ, Dosanjh, RS, Doucas, G, Duba, CA, Duncan, FA, Dunford, M, Dunmore, JA, Earle, ED, Elliott, SR, Evans, HC, Ewan, GT, Farine, J, Fergani, H, Fleurot, F, Formaggio, JA, Frati, W, Fulsom, BG, Gagnon, N, Goon, JT, Graham, K, Hahn, RL, Hallin, AL, Hallman, ED, Handler, WB, Hargrove, CK, Harvey, PJ, Hazama, R, Heeger, KM, Heelan, L, Heintzelman, WJ, Heise, J, Helmer, RL, Hemingway, RJ, Hime, A, Howe, MA, Huang, M, Inrig, E, Jagam, P, Jelley, NA, Klein, JR, Kormos, LL, Kos, MS, Kruger, A, Kraus, C, Krauss, CB, Krumins, AV, Kutter, T, Kyba, CCM, Labranche, H, Lange, R, Law, J, Lawson, IT, Lesko, KT, Leslie, JR, Levine, I, Loach, JC, Luoma, S, MacLellan, R, Majerus, S, Maneira, J, Marino, AD, McCauley, N, McDonald, AB, McGee, S, Mifflin, C, Miknaitis, KKS, Nickel, BG, Noble, AJ, Norman, EB, Oblath, NS, Okada, CE, O'Keeffe, HM, Ollerhead, RW, Gann, GDO, Orrell, JL, Oser, SM, Ouvarova, T, Peeters, SJM, Poon, AWP, Pun, CSJ, Rielage, K, Robertson, BC, Robertson, RGH, Rollin, E, Rosendahl, SSE, Schwendener, MH, Seibert, SR, Simard, O, Simpson, JJ, Sims, CJ, Sinclair, D, Sinclair, L, Skensved, P, Smith, MWE, Stokstad, RG, Stonehill, LC, Tafirout, R, Takeuchi, Y, Tesic, G, Thomson, M, Tsang, KV, Tsui, T, Van Berg, R, Virtue, CJ, Wall, BL, Waller, D, Waltham, CE, Tseung, HWC, Wark, DL, Wendland, J, West, N, Wilkerson, JF, Wilson, JR, Wouters, JM, Yeh, M, Zuber, K, and Collaboration, SNO

Published
2005

27. Design Constraints for a WIMP Dark Matter and pp Solar Neutrino Liquid Neon Scintillation Detector

Author

Boulay, MG, Hime, A, and Lidgard, J

Subjects
Physics::Instrumentation and Detectors, Astrophysics (astro-ph), FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Astrophysics, Nuclear Experiment
Abstract

Detailed Monte-Carlo simulations were used to evaluate the performance of a liquid neon scintillation detector for dark matter and low-energy solar neutrino interactions. A maximum-likelihood event vertex fitter including PMT time information was developed, which significantly improves position resolution over spatial-only algorithms, and substantially decreases the required detector size and achievable analysis energy threshold. The ultimate sensitivity to WIMP dark matter and the pp flux uncertainty are evaluated as a function of detector size. The dependence on the neon scintillation and PMT properties are evaluated. A 300 cm radius detector would allow a ~13 keV threshold, a pp flux uncertainty of ~1%, and limits on the spin-independent WIMP-nucleon cross-section of ~10^{-46} cm^2 for a 100 GeV WIMP, using commercially available PMTs. Detector response calibration and background requirements for a precision pp measurement are defined. Internal radioactivity requirements for uranium, thorium, and krypton are specified, and it is shown that the PMT data could be used for an in-situ calibration of the troublesome krypton-85. A set of measurements of neon scintillation properties and PMT characteristics are outlined which will be needed in order to evaluate feasibility and fully optimize the design of a neon-based detector., Comment: 27 pages, 43 figures

Published
2004
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28. Measurement of the rate of nu(e) + d --p + p + e(-) interactions produced by (8)B solar neutrinos at the Sudbury Neutrino Observatory

Author

Ahmad, QR, Allen, RC, Andersen, TC, Anglin, JD, Bühler, G, Barton, JC, Beier, EW, Bercovitch, M, Bigu, J, Biller, S, Black, RA, Blevis, I, Boardman, RJ, Boger, J, Bonvin, E, Boulay, MG, Bowler, MG, Bowles, TJ, Brice, SJ, Browne, MC, Bullard, TV, Burritt, TH, Cameron, K, Cameron, J, Chan, YD, Chen, M, Chen, HH, Chen, X, Chon, MC, Cleveland, BT, Clifford, ET, Cowan, JH, Cowen, DF, Cox, GA, Dai, Y, Dai, X, Dalnoki-Veress, F, Davidson, WF, Doe, PJ, Doucas, G, Dragowsky, MR, Duba, CA, Duncan, FA, Dunmore, J, Earle, ED, Elliott, SR, Evans, HC, Ewan, GT, Farine, J, Fergani, H, Ferraris, AP, Ford, RJ, Fowler, MM, Frame, K, Frank, ED, Frati, W, Germani, JV, Gil, S, Goldschmidt, A, Grant, DR, Hahn, RL, Hallin, AL, Hallman, ED, Hamer, A, Hamian, AA, Haq, RU, Hargrove, CK, Harvey, PJ, Hazama, R, Heaton, R, Heeger, KM, Heintzelman, WJ, Heise, J, Helmer, RL, Hepburn, JD, Heron, H, Hewett, J, Hime, A, Howe, M, Hykawy, JG, Isaac, MC, Jagam, P, Jelley, NA, Jillings, C, Jonkmans, G, Karn, J, Keener, PT, Kirch, K, Klein, JR, Knox, AB, Komar, RJ, Kouzes, R, Kutter, T, Kyba, CC, Law, J, Lawson, IT, Lay, M, Lee, HW, Lesko, KT, Leslie, JR, Levine, I, Locke, W, Lowry, MM, Luoma, S, Lyon, J, Majerus, S, Mak, HB, Marino, AD, McCauley, N, McDonald, AB, McDonald, DS, McFarlane, K, McGregor, G, McLatchie, W, Meijer Drees, R, Mes, H, Mifflin, C, Miller, GG, Milton, G, Moffat, BA, Moorhead, M, Nally, CW, Neubauer, MS, Newcomer, FM, Ng, HS, Noble, AJ, Norman, EB, Novikov, VM, O'Neill, M, Okada, CE, Ollerhead, RW, Omori, M, Orrell, JL, Oser, SM, Poon, AW, Radcliffe, TJ, Roberge, A, Robertson, BC, Robertson, RG, Rowley, JK, Rusu, VL, Saettler, E, Schaffer, KK, Schuelke, A, Schwendener, MH, Seifert, H, Shatkay, M, Simpson, JJ, Sinclair, D, Skensved, P, Smith, AR, Smith, MW, Starinsky, N, Steiger, TD, Stokstad, RG, Storey, RS, Sur, B, Tafirout, R, Tagg, N, Tanner, NW, Taplin, RK, Thorman, M, Thornewell, P, Trent, PT, Tserkovnyak, YI, Van Berg, R, Van de Water, RG, Virtue, CJ, Waltham, CE, Wang, JX, Wark, DL, West, N, Wilhelmy, JB, Wilkerson, JF, Wilson, J, Wittich, P, Wouters, JM, and Yeh, M

Subjects
High Energy Physics::Experiment, Astrophysics::Earth and Planetary Astrophysics
Abstract

Solar neutrinos from (8)B decay have been detected at the Sudbury Neutrino Observatory via the charged current (CC) reaction on deuterium and the elastic scattering (ES) of electrons. The flux of nu(e)'s is measured by the CC reaction rate to be straight phi(CC)(nu(e)) = 1.75 +/- 0.07(stat)(+0.12)(-0.11)(syst) +/- 0.05(theor) x 10(6) cm(-2) s(-1). Comparison of straight phi(CC)(nu(e)) to the Super-Kamiokande Collaboration's precision value of the flux inferred from the ES reaction yields a 3.3 sigma difference, assuming the systematic uncertainties are normally distributed, providing evidence of an active non- nu(e) component in the solar flux. The total flux of active 8B neutrinos is determined to be 5.44+/-0.99 x 10(6) cm(-2) s(-1).

Published
2001

29. First Direct Detection Constraints on Planck-Scale Mass Dark Matter with Multiple-Scatter Signatures Using the DEAP-3600 Detector.

Author

Adhikari P, Ajaj R, Alpízar-Venegas M, Auty DJ, Benmansour H, Bina CE, Bonivento W, Boulay MG, Cadeddu M, Cai B, Cárdenas-Montes M, Cavuoti S, Chen Y, Cleveland BT, Corning JM, Daugherty S, DelGobbo P, Di Stefano P, Doria L, Dunford M, Ellingwood E, Erlandson A, Farahani SS, Fatemighomi N, Fiorillo G, Gallacher D, García Abia P, Garg S, Giampa P, Goeldi D, Gorel P, Graham K, Grobov A, Hallin AL, Hamstra M, Hugues T, Ilyasov A, Joy A, Jigmeddorj B, Jillings CJ, Kamaev O, Kaur G, Kemp A, Kochanek I, Kuźniak M, Lai M, Langrock S, Lehnert B, Leonhardt A, Levashko N, Li X, Lissia M, Litvinov O, Lock J, Longo G, Machulin I, McDonald AB, McElroy T, McLaughlin JB, Mielnichuk C, Mirasola L, Monroe J, Oliviéro G, Pal S, Peeters SJM, Perry M, Pesudo V, Picciau E, Piro MC, Pollmann TR, Raj N, Rand ET, Rethmeier C, Retière F, Rodríguez-García I, Roszkowski L, Ruhland JB, Sanchez García E, Sánchez-Pastor T, Santorelli R, Seth S, Sinclair D, Skensved P, Smith B, Smith NJT, Sonley T, Stainforth R, Stringer M, Sur B, Vázquez-Jáuregui E, Viel S, Walding J, Waqar M, Ward M, Westerdale S, Willis J, and Zuñiga-Reyes A

Abstract

Dark matter with Planck-scale mass (≃10^{19}  GeV/c^{2}) arises in well-motivated theories and could be produced by several cosmological mechanisms. A search for multiscatter signals from supermassive dark matter was performed with a blind analysis of data collected over a 813 d live time with DEAP-3600, a 3.3 t single-phase liquid argon-based detector at SNOLAB. No candidate signals were observed, leading to the first direct detection constraints on Planck-scale mass dark matter. Leading limits constrain dark matter masses between 8.3×10^{6} and 1.2×10^{19}  GeV/c^{2}, and ^{40}Ar-scattering cross sections between 1.0×10^{-23} and 2.4×10^{-18}  cm^{2}. These results are interpreted as constraints on composite dark matter models with two different nucleon-to-nuclear cross section scalings.

Published
2022
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30. Pulse-shape discrimination against low-energy Ar-39 beta decays in liquid argon with 4.5 tonne-years of DEAP-3600 data.

Author

Adhikari P, Ajaj R, Alpízar-Venegas M, Amaudruz PA, Auty DJ, Batygov M, Beltran B, Benmansour H, Bina CE, Bonatt J, Bonivento W, Boulay MG, Broerman B, Bueno JF, Burghardt PM, Butcher A, Cadeddu M, Cai B, Cárdenas-Montes M, Cavuoti S, Chen M, Chen Y, Cleveland BT, Corning JM, Cranshaw D, Daugherty S, DelGobbo P, Dering K, DiGioseffo J, Di Stefano P, Doria L, Duncan FA, Dunford M, Ellingwood E, Erlandson A, Farahani SS, Fatemighomi N, Fiorillo G, Florian S, Flower T, Ford RJ, Gagnon R, Gallacher D, García Abia P, Garg S, Giampa P, Goeldi D, Golovko V, Gorel P, Graham K, Grant DR, Grobov A, Hallin AL, Hamstra M, Harvey PJ, Hearns C, Hugues T, Ilyasov A, Joy A, Jigmeddorj B, Jillings CJ, Kamaev O, Kaur G, Kemp A, Kochanek I, Kuźniak M, Lai M, Langrock S, Lehnert B, Leonhardt A, Levashko N, Li X, Lidgard J, Lindner T, Lissia M, Lock J, Longo G, Machulin I, McDonald AB, McElroy T, McGinn T, McLaughlin JB, Mehdiyev R, Mielnichuk C, Monroe J, Nadeau P, Nantais C, Ng C, Noble AJ, O'Dwyer E, Oliviéro G, Ouellet C, Pal S, Pasuthip P, Peeters SJM, Perry M, Pesudo V, Picciau E, Piro MC, Pollmann TR, Rand ET, Rethmeier C, Retière F, Rodríguez-García I, Roszkowski L, Ruhland JB, Sánchez-García E, Santorelli R, Sinclair D, Skensved P, Smith B, Smith NJT, Sonley T, Soukup J, Stainforth R, Stone C, Strickland V, Stringer M, Sur B, Tang J, Vázquez-Jáuregui E, Viel S, Walding J, Waqar M, Ward M, Westerdale S, Willis J, and Zuñiga-Reyes A

Abstract

The DEAP-3600 detector searches for the scintillation signal from dark matter particles scattering on a 3.3 tonne liquid argon target. The largest background comes from 39 Ar beta decays and is suppressed using pulse-shape discrimination (PSD). We use two types of PSD estimator: the prompt-fraction, which considers the fraction of the scintillation signal in a narrow and a wide time window around the event peak, and the log-likelihood-ratio, which compares the observed photon arrival times to a signal and a background model. We furthermore use two algorithms to determine the number of photons detected at a given time: (1) simply dividing the charge of each PMT pulse by the mean single-photoelectron charge, and (2) a likelihood analysis that considers the probability to detect a certain number of photons at a given time, based on a model for the scintillation pulse shape and for afterpulsing in the light detectors. The prompt-fraction performs approximately as well as the log-likelihood-ratio PSD algorithm if the photon detection times are not biased by detector effects. We explain this result using a model for the information carried by scintillation photons as a function of the time when they are detected., (© The Author(s) 2021.)

Published
2021
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31. First Results from the DEAP-3600 Dark Matter Search with Argon at SNOLAB.

Author

Amaudruz PA, Baldwin M, Batygov M, Beltran B, Bina CE, Bishop D, Bonatt J, Boorman G, Boulay MG, Broerman B, Bromwich T, Bueno JF, Burghardt PM, Butcher A, Cai B, Chan S, Chen M, Chouinard R, Cleveland BT, Cranshaw D, Dering K, DiGioseffo J, Dittmeier S, Duncan FA, Dunford M, Erlandson A, Fatemighomi N, Florian S, Flower A, Ford RJ, Gagnon R, Giampa P, Golovko VV, Gorel P, Gornea R, Grace E, Graham K, Gulyev E, Hakobyan R, Hall A, Hallin AL, Hamstra M, Harvey PJ, Hearns C, Jillings CJ, Kamaev O, Kemp A, Kuźniak M, Langrock S, La Zia F, Lehnert B, Lidgard JJ, Lim C, Lindner T, Linn Y, Liu S, Majewski P, Mathew R, McDonald AB, McElroy T, McGinn T, McLaughlin JB, Mead S, Mehdiyev R, Mielnichuk C, Monroe J, Muir A, Nadeau P, Nantais C, Ng C, Noble AJ, O'Dwyer E, Ohlmann C, Olchanski K, Olsen KS, Ouellet C, Pasuthip P, Peeters SJM, Pollmann TR, Rand ET, Rau W, Rethmeier C, Retière F, Seeburn N, Shaw B, Singhrao K, Skensved P, Smith B, Smith NJT, Sonley T, Soukup J, Stainforth R, Stone C, Strickland V, Sur B, Tang J, Taylor J, Veloce L, Vázquez-Jáuregui E, Walding J, Ward M, Westerdale S, Woolsey E, and Zielinski J

Abstract

This Letter reports the first results of a direct dark matter search with the DEAP-3600 single-phase liquid argon (LAr) detector. The experiment was performed 2 km underground at SNOLAB (Sudbury, Canada) utilizing a large target mass, with the LAr target contained in a spherical acrylic vessel of 3600 kg capacity. The LAr is viewed by an array of PMTs, which would register scintillation light produced by rare nuclear recoil signals induced by dark matter particle scattering. An analysis of 4.44 live days (fiducial exposure of 9.87 ton day) of data taken during the initial filling phase demonstrates the best electronic recoil rejection using pulse-shape discrimination in argon, with leakage <1.2×10^{-7} (90% C.L.) between 15 and 31  keV&#95;{ee}. No candidate signal events are observed, which results in the leading limit on weakly interacting massive particle (WIMP)-nucleon spin-independent cross section on argon, <1.2×10^{-44}  cm^{2} for a 100  GeV/c^{2} WIMP mass (90% C.L.).

Published
2018
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32. Do academic knowledge brokers exist? Using social network analysis to explore academic research-to-policy networks from six schools of public health in Kenya.

Author

Jessani NS, Boulay MG, and Bennett SC

Subjects
Counseling, Decision Making, Evidence-Based Practice, Health Personnel, Health Services Research, Humans, Kenya, Administrative Personnel statistics & numerical data, Schools, Public Health, Social Support, Translational Research, Biomedical methods
Abstract

The potential for academic research institutions to facilitate knowledge exchange and influence evidence-informed decision-making has been gaining ground. Schools of public health (SPHs) may play a key knowledge brokering role-serving as agencies of and for development. Understanding academic-policymaker networks can facilitate the enhancement of links between policymakers and academic faculty at SPHs, as well as assist in identifying academic knowledge brokers (KBs). Using a census approach, we administered a sociometric survey to academic faculty across six SPHs in Kenya to construct academic-policymaker networks. We identified academic KBs using social network analysis (SNA) in a two-step approach: First, we ranked individuals based on (1) number of policymakers in their network; (2) number of academic peers who report seeking them out for advice on knowledge translation and (3) their network position as 'inter-group connectors'. Second, we triangulated the three scores and re-ranked individuals. Academic faculty scoring within the top decile across all three measures were classified as KBs. Results indicate that each SPH commands a variety of unique as well as overlapping relationships with national ministries in Kenya. Of 124 full-time faculty, we identified 7 KBs in 4 of the 6 SPHs. Those scoring high on the first measure were not necessarily the same individuals scoring high on the second. KBs were also situated in a wide range along the 'connector/betweenness' measure. We propose that a composite score rather than traditional 'betweenness centrality', provides an alternative means of identifying KBs within these networks. In conclusion, SNA is a valuable tool for identifying academic-policymaker networks in Kenya. More efforts to conduct similar network studies would permit SPH leadership to identify existing linkages between faculty and policymakers, shared linkages with other SPHs and gaps so as to contribute to evidence-informed health policies., (© The Author 2015. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine.)

Published
2016
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33. Independent measurement of the total active 8B solar neutrino flux using an array of 3He proportional counters at the Sudbury Neutrino Observatory.

Author

Aharmim B, Ahmed SN, Amsbaugh JF, Anthony AE, Banar J, Barros N, Beier EW, Bellerive A, Beltran B, Bergevin M, Biller SD, Boudjemline K, Boulay MG, Bowles TJ, Browne MC, Bullard TV, Burritt TH, Cai B, Chan YD, Chauhan D, Chen M, Cleveland BT, Cox-Mobrand GA, Currat CA, Dai X, Deng H, Detwiler J, DiMarco M, Doe PJ, Doucas G, Drouin PL, Duba CA, Duncan FA, Dunford M, Earle ED, Elliott SR, Evans HC, Ewan GT, Farine J, Fergani H, Fleurot F, Ford RJ, Formaggio JA, Fowler MM, Gagnon N, Germani JV, Goldschmidt A, Goon JT, Graham K, Guillian E, Habib S, Hahn RL, Hallin AL, Hallman ED, Hamian AA, Harper GC, Harvey PJ, Hazama R, Heeger KM, Heintzelman WJ, Heise J, Helmer RL, Henning R, Hime A, Howard C, Howe MA, Huang M, Jagam P, Jamieson B, Jelley NA, Keeter KJ, Klein JR, Kormos LL, Kos M, Krüger A, Kraus C, Krauss CB, Kutter T, Kyba CC, Lange R, Law J, Lawson IT, Lesko KT, Leslie JR, Loach JC, MacLellan R, Majerus S, Mak HB, Maneira J, Martin R, McBryde K, McCauley N, McDonald AB, McGee S, Mifflin C, Miller GG, Miller ML, Monreal B, Monroe J, Morissette B, Myers A, Nickel BG, Noble AJ, Oblath NS, O'Keeffe HM, Ollerhead RW, Gann GD, Oser SM, Ott RA, Peeters SJ, Poon AW, Prior G, Reitzner SD, Rielage K, Robertson BC, Robertson RG, Rollin E, Schwendener MH, Secrest JA, Seibert SR, Simard O, Simpson JJ, Sinclair L, Skensved P, Smith MW, Steiger TD, Stonehill LC, Tesić G, Thornewell PM, Tolich N, Tsui T, Tunnell CD, Van Wechel T, Van Berg R, VanDevender BA, Virtue CJ, Walker TJ, Wall BL, Waller D, Tseung HW, Wendland J, West N, Wilhelmy JB, Wilkerson JF, Wilson JR, Wouters JM, Wright A, Yeh M, Zhang F, and Zuber K

Abstract

The Sudbury Neutrino Observatory (SNO) used an array of 3He proportional counters to measure the rate of neutral-current interactions in heavy water and precisely determined the total active (nu&#95;x) 8B solar neutrino flux. This technique is independent of previous methods employed by SNO. The total flux is found to be 5.54&#95;-0.31;+0.33(stat)-0.34+0.36(syst)x10(6) cm(-2) s(-1), in agreement with previous measurements and standard solar models. A global analysis of solar and reactor neutrino results yields Deltam2=7.59&#95;-0.21;+0.19x10(-5) eV2 and theta=34.4&#95;-1.2;+1.3 degrees. The uncertainty on the mixing angle has been reduced from SNO's previous results.

Published
2008
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34. Measurement of the total active 8B solar neutrino flux at the Sudbury Neutrino Observatory with enhanced neutral current sensitivity.

Author

Ahmed SN, Anthony AE, Beier EW, Bellerive A, Biller SD, Boger J, Boulay MG, Bowler MG, Bowles TJ, Brice SJ, Bullard TV, Chan YD, Chen M, Chen X, Cleveland BT, Cox GA, Dai X, Dalnoki-Veress F, Doe PJ, Dosanjh RS, Doucas G, Dragowsky MR, Duba CA, Duncan FA, Dunford M, Dunmore JA, Earle ED, Elliott SR, Evans HC, Ewan GT, Farine J, Fergani H, Fleurot F, Formaggio JA, Fowler MM, Frame K, Fulsom BG, Gagnon N, Graham K, Grant DR, Hahn RL, Hall JC, Hallin AL, Hallman ED, Hamer AS, Handler WB, Hargrove CK, Harvey PJ, Hazama R, Heeger KM, Heintzelman WJ, Heise J, Helmer RL, Hemingway RJ, Hime A, Howe MA, Jagam P, Jelley NA, Klein JR, Kos MS, Krumins AV, Kutter T, Kyba CC, Labranche H, Lange R, Law J, Lawson IT, Lesko KT, Leslie JR, Levine I, Luoma S, MacLellan R, Majerus S, Mak HB, Maneira J, Marino AD, McCauley N, McDonald AB, McGee S, McGregor G, Mifflin C, Miknaitis KK, Miller GG, Moffat BA, Nally CW, Nickel BG, Noble AJ, Norman EB, Oblath NS, Okada CE, Ollerhead RW, Orrell JL, Oser SM, Ouellet C, Peeters SJ, Poon AW, Robertson BC, Robertson RG, Rollin E, Rosendahl SS, Rusu VL, Schwendener MH, Simard O, Simpson JJ, Sims CJ, Sinclair D, Skensved P, Smith MW, Starinsky N, Stokstad RG, Stonehill LC, Tafirout R, Takeuchi Y, Tesić G, Thomson M, Thorman M, Van Berg R, Van de Water RG, Virtue CJ, Wall BL, Waller D, Waltham CE, Tseung HW, Wark DL, West N, Wilhelmy JB, Wilkerson JF, Wilson JR, Wouters JM, Yeh M, and Zuber K

Abstract

The Sudbury Neutrino Observatory has precisely determined the total active (nu(x)) 8B solar neutrino flux without assumptions about the energy dependence of the nu(e) survival probability. The measurements were made with dissolved NaCl in heavy water to enhance the sensitivity and signature for neutral-current interactions. The flux is found to be 5.21 +/- 0.27(stat)+/-0.38(syst) x 10(6) cm(-2) s(-1), in agreement with previous measurements and standard solar models. A global analysis of these and other solar and reactor neutrino results yields Deltam(2)=7.1(+1.2)(-0.6) x 10(-5) eV(2) and theta=32.5(+2.4)(-2.3) degrees. Maximal mixing is rejected at the equivalent of 5.4 standard deviations.

Published
2004
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35. Constraints on nucleon decay via invisible modes from the Sudbury Neutrino Observatory.

Author

Ahmed SN, Anthony AE, Beier EW, Bellerive A, Biller SD, Boger J, Boulay MG, Bowler MG, Bowles TJ, Brice SJ, Bullard TV, Chan YD, Chen M, Chen X, Cleveland BT, Cox GA, Dai X, Dalnoki-Veress F, Doe PJ, Dosanjh RS, Doucas G, Dragowsky MR, Duba CA, Duncan FA, Dunford M, Dunmore JA, Earle ED, Elliott SR, Evans HC, Ewan GT, Farine J, Fergani H, Fleurot F, Formaggio JA, Fowler MM, Frame K, Frati W, Fulsom BG, Gagnon N, Graham K, Grant DR, Hahn RL, Hall JC, Hallin AL, Hallman ED, Hamer AS, Handler WB, Hargrove CK, Harvey PJ, Hazama R, Heeger KM, Heintzelman WJ, Heise J, Helmer RL, Hemingway RJ, Hime A, Howe MA, Jagam P, Jelley NA, Klein JR, Kos MS, Krumins AV, Kutter T, Kyba CC, Labranche H, Lange R, Law J, Lawson IT, Lesko KT, Leslie JR, Levine I, Luoma S, MacLellan R, Majerus S, Mak HB, Maneira J, Marino AD, McCauley N, McDonald AB, McGee S, McGregor G, Mifflin C, Miknaitis KK, Miller GG, Moffat BA, Nally CW, Neubauer MS, Nickel BG, Noble AJ, Norman EB, Oblath NS, Okada CE, Ollerhead RW, Orrell JL, Oser SM, Ouellet C, Peeters SJ, Poon AW, Robertson BC, Robertson RG, Rollin E, Rosendahl SS, Rusu VL, Schwendener MH, Simard O, Simpson JJ, Sims CJ, Sinclair D, Skensved P, Smith MW, Starinsky N, Stokstad RG, Stonehill LC, Tafirout R, Takeuchi Y, Tesić G, Thomson M, Thorman M, Van Berg R, Van de Water RG, Virtue CJ, Wall BL, Waller D, Waltham CE, Tseung HW, Wark DL, West N, Wilhelmy JB, Wilkerson JF, Wilson JR, Wittich P, Wouters JM, Yeh M, and Zuber K

Abstract

Data from the Sudbury Neutrino Observatory have been used to constrain the lifetime for nucleon decay to "invisible" modes, such as n-->3nu. The analysis was based on a search for gamma rays from the deexcitation of the residual nucleus that would result from the disappearance of either a proton or neutron from 16O. A limit of tau(inv)>2 x 10(29) yr is obtained at 90% confidence for either neutron- or proton-decay modes. This is about an order of magnitude more stringent than previous constraints on invisible proton-decay modes and 400 times more stringent than similar neutron modes.

Published
2004
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36. Measurement of day and night neutrino energy spectra at SNO and constraints on neutrino mixing parameters.

Author

Ahmad QR, Allen RC, Andersen TC, Anglin JD, Barton JC, Beier EW, Bercovitch M, Bigu J, Biller SD, Black RA, Blevis I, Boardman RJ, Boger J, Bonvin E, Boulay MG, Bowler MG, Bowles TJ, Brice SJ, Browne MC, Bullard TV, Bühler G, Cameron J, Chan YD, Chen HH, Chen M, Chen X, Cleveland BT, Clifford ET, Cowan JH, Cowen DF, Cox GA, Dai X, Dalnoki-Veress F, Davidson WF, Doe PJ, Doucas G, Dragowsky MR, Duba CA, Duncan FA, Dunford M, Dunmore JA, Earle ED, Elliott SR, Evans HC, Ewan GT, Farine J, Fergani H, Ferraris AP, Ford RJ, Formaggio JA, Fowler MM, Frame K, Frank ED, Frati W, Gagnon N, Germani JV, Gil S, Graham K, Grant DR, Hahn RL, Hallin AL, Hallman ED, Hamer AS, Hamian AA, Handler WB, Haq RU, Hargrove CK, Harvey PJ, Hazama R, Heeger KM, Heintzelman WJ, Heise J, Helmer RL, Hepburn JD, Heron H, Hewett J, Hime A, Howe M, Hykawy JG, Isaac MC, Jagam P, Jelley NA, Jillings C, Jonkmans G, Kazkaz K, Keener PT, Klein JR, Knox AB, Komar RJ, Kouzes R, Kutter T, Kyba CC, Law J, Lawson IT, Lay M, Lee HW, Lesko KT, Leslie JR, Levine I, Locke W, Luoma S, Lyon J, Majerus S, Mak HB, Maneira J, Manor J, Marino AD, McCauley N, McDonald AB, McDonald DS, McFarlane K, McGregor G, Meijer Drees R, Mifflin C, Miller GG, Milton G, Moffat BA, Moorhead M, Nally CW, Neubauer MS, Newcomer FM, Ng HS, Noble AJ, Norman EB, Novikov VM, O'Neill M, Okada CE, Ollerhead RW, Omori M, Orrell JL, Oser SM, Poon AW, Radcliffe TJ, Roberge A, Robertson BC, Robertson RG, Rosendahl SS, Rowley JK, Rusu VL, Saettler E, Schaffer KK, Schwendener MH, Schülke A, Seifert H, Shatkay M, Simpson JJ, Sims CJ, Sinclair D, Skensved P, Smith AR, Smith MW, Spreitzer T, Starinsky N, Steiger TD, Stokstad RG, Stonehill LC, Storey RS, Sur B, Tafirout R, Tagg N, Tanner NW, Taplin RK, Thorman M, Thornewell PM, Trent PT, Tserkovnyak YI, Van Berg R, Van de Water RG, Virtue CJ, Waltham CE, Wang JX, Wark DL, West N, Wilhelmy JB, Wilkerson JF, Wilson JR, Wittich P, Wouters JM, and Yeh M

Abstract

The Sudbury Neutrino Observatory (SNO) has measured day and night solar neutrino energy spectra and rates. For charged current events, assuming an undistorted 8B spectrum, the night minus day rate is 14.0%+/-6.3%(+1.5%)(-1.4%) of the average rate. If the total flux of active neutrinos is additionally constrained to have no asymmetry, the nu(e) asymmetry is found to be 7.0%+/-4.9%(+1.3%)(-1.2%). A global solar neutrino analysis in terms of matter-enhanced oscillations of two active flavors strongly favors the large mixing angle solution.

Published
2002
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37. Direct evidence for neutrino flavor transformation from neutral-current interactions in the Sudbury Neutrino Observatory.

Author

Ahmad QR, Allen RC, Andersen TC, D Anglin J, Barton JC, Beier EW, Bercovitch M, Bigu J, Biller SD, Black RA, Blevis I, Boardman RJ, Boger J, Bonvin E, Boulay MG, Bowler MG, Bowles TJ, Brice SJ, Browne MC, Bullard TV, Bühler G, Cameron J, Chan YD, Chen HH, Chen M, Chen X, Cleveland BT, Clifford ET, Cowan JH, Cowen DF, Cox GA, Dai X, Dalnoki-Veress F, Davidson WF, Doe PJ, Doucas G, Dragowsky MR, Duba CA, Duncan FA, Dunford M, Dunmore JA, Earle ED, Elliott SR, Evans HC, Ewan GT, Farine J, Fergani H, Ferraris AP, Ford RJ, Formaggio JA, Fowler MM, Frame K, Frank ED, Frati W, Gagnon N, Germani JV, Gil S, Graham K, Grant DR, Hahn RL, Hallin AL, Hallman ED, Hamer AS, Hamian AA, Handler WB, Haq RU, Hargrove CK, Harvey PJ, Hazama R, Heeger KM, Heintzelman WJ, Heise J, Helmer RL, Hepburn JD, Heron H, Hewett J, Hime A, Howe M, Hykawy JG, Isaac MC, Jagam P, Jelley NA, Jillings C, Jonkmans G, Kazkaz K, Keener PT, Klein JR, Knox AB, Komar RJ, Kouzes R, Kutter T, Kyba CC, Law J, Lawson IT, Lay M, Lee HW, Lesko KT, Leslie JR, Levine I, Locke W, Luoma S, Lyon J, Majerus S, Mak HB, Maneira J, Manor J, Marino AD, McCauley N, McDonald AB, McDonald DS, McFarlane K, McGregor G, Meijer Drees R, Mifflin C, Miller GG, Milton G, Moffat BA, Moorhead M, Nally CW, Neubauer MS, Newcomer FM, Ng HS, Noble AJ, Norman EB, Novikov VM, O'Neill M, Okada CE, Ollerhead RW, Omori M, Orrell JL, Oser SM, Poon AW, Radcliffe TJ, Roberge A, Robertson BC, Robertson RG, Rosendahl SS, Rowley JK, Rusu VL, Saettler E, Schaffer KK, Schwendener MH, Schülke A, Seifert H, Shatkay M, Simpson JJ, Sims CJ, Sinclair D, Skensved P, Smith AR, Smith MW, Spreitzer T, Starinsky N, Steiger TD, Stokstad RG, Stonehill LC, Storey RS, Sur B, Tafirout R, Tagg N, Tanner NW, Taplin RK, Thorman M, Thornewell PM, Trent PT, Tserkovnyak YI, Van Berg R, Van de Water RG, Virtue CJ, Waltham CE, Wang JX, Wark DL, West N, Wilhelmy JB, Wilkerson JF, Wilson JR, Wittich P, Wouters JM, and Yeh M

Abstract

Observations of neutral-current nu interactions on deuterium in the Sudbury Neutrino Observatory are reported. Using the neutral current (NC), elastic scattering, and charged current reactions and assuming the standard 8B shape, the nu(e) component of the 8B solar flux is phis(e) = 1.76(+0.05)(-0.05)(stat)(+0.09)(-0.09)(syst) x 10(6) cm(-2) s(-1) for a kinetic energy threshold of 5 MeV. The non-nu(e) component is phi(mu)(tau) = 3.41(+0.45)(-0.45)(stat)(+0.48)(-0.45)(syst) x 10(6) cm(-2) s(-1), 5.3sigma greater than zero, providing strong evidence for solar nu(e) flavor transformation. The total flux measured with the NC reaction is phi(NC) = 5.09(+0.44)(-0.43)(stat)(+0.46)(-0.43)(syst) x 10(6) cm(-2) s(-1), consistent with solar models.

Published
2002
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38. Measurement of the rate of nu(e) + d --> p + p + e(-) interactions produced by (8)B solar neutrinos at the Sudbury Neutrino Observatory.

Author

Ahmad QR, Allen RC, Andersen TC, Anglin JD, Bühler G, Barton JC, Beier EW, Bercovitch M, Bigu J, Biller S, Black RA, Blevis I, Boardman RJ, Boger J, Bonvin E, Boulay MG, Bowler MG, Bowles TJ, Brice SJ, Browne MC, Bullard TV, Burritt TH, Cameron K, Cameron J, Chan YD, Chen M, Chen HH, Chen X, Chon MC, Cleveland BT, Clifford ET, Cowan JH, Cowen DF, Cox GA, Dai Y, Dai X, Dalnoki-Veress F, Davidson WF, Doe PJ, Doucas G, Dragowsky MR, Duba CA, Duncan FA, Dunmore J, Earle ED, Elliott SR, Evans HC, Ewan GT, Farine J, Fergani H, Ferraris AP, Ford RJ, Fowler MM, Frame K, Frank ED, Frati W, Germani JV, Gil S, Goldschmidt A, Grant DR, Hahn RL, Hallin AL, Hallman ED, Hamer A, Hamian AA, Haq RU, Hargrove CK, Harvey PJ, Hazama R, Heaton R, Heeger KM, Heintzelman WJ, Heise J, Helmer RL, Hepburn JD, Heron H, Hewett J, Hime A, Howe M, Hykawy JG, Isaac MC, Jagam P, Jelley NA, Jillings C, Jonkmans G, Karn J, Keener PT, Kirch K, Klein JR, Knox AB, Komar RJ, Kouzes R, Kutter T, Kyba CC, Law J, Lawson IT, Lay M, Lee HW, Lesko KT, Leslie JR, Levine I, Locke W, Lowry MM, Luoma S, Lyon J, Majerus S, Mak HB, Marino AD, McCauley N, McDonald AB, McDonald DS, McFarlane K, McGregor G, McLatchie W, Meijer Drees R, Mes H, Mifflin C, Miller GG, Milton G, Moffat BA, Moorhead M, Nally CW, Neubauer MS, Newcomer FM, Ng HS, Noble AJ, Norman EB, Novikov VM, O'Neill M, Okada CE, Ollerhead RW, Omori M, Orrell JL, Oser SM, Poon AW, Radcliffe TJ, Roberge A, Robertson BC, Robertson RG, Rowley JK, Rusu VL, Saettler E, Schaffer KK, Schuelke A, Schwendener MH, Seifert H, Shatkay M, Simpson JJ, Sinclair D, Skensved P, Smith AR, Smith MW, Starinsky N, Steiger TD, Stokstad RG, Storey RS, Sur B, Tafirout R, Tagg N, Tanner NW, Taplin RK, Thorman M, Thornewell P, Trent PT, Tserkovnyak YI, Van Berg R, Van de Water RG, Virtue CJ, Waltham CE, Wang JX, Wark DL, West N, Wilhelmy JB, Wilkerson JF, Wilson J, Wittich P, Wouters JM, and Yeh M

Abstract

Solar neutrinos from (8)B decay have been detected at the Sudbury Neutrino Observatory via the charged current (CC) reaction on deuterium and the elastic scattering (ES) of electrons. The flux of nu(e)'s is measured by the CC reaction rate to be straight phi(CC)(nu(e)) = 1.75 +/- 0.07(stat)(+0.12)(-0.11)(syst) +/- 0.05(theor) x 10(6) cm(-2) s(-1). Comparison of straight phi(CC)(nu(e)) to the Super-Kamiokande Collaboration's precision value of the flux inferred from the ES reaction yields a 3.3 sigma difference, assuming the systematic uncertainties are normally distributed, providing evidence of an active non- nu(e) component in the solar flux. The total flux of active 8B neutrinos is determined to be 5.44+/-0.99 x 10(6) cm(-2) s(-1).

Published
2001
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39. Mediators, initiating the inflammatory response, released in organ culture by full-thickness human skin explants exposed to the irritant, sulfur mustard.

Author

Rikimaru T, Nakamura M, Yano T, Beck G, Habicht GS, Rennie LL, Widra M, Hirshman CA, Boulay MG, and Spannhake EW

Subjects
Administration, Cutaneous, Dinoprostone metabolism, Histamine Release drug effects, Humans, Hydrolases metabolism, Hydroxyproline metabolism, Inflammation chemically induced, Interleukin-1 metabolism, L-Lactate Dehydrogenase metabolism, Lysosomes enzymology, Mast Cells metabolism, Mustard Gas administration & dosage, Organ Culture Techniques, Proteins metabolism, Skin cytology, Skin drug effects, Inflammation metabolism, Skin metabolism
Abstract

Mediators released from injured human skin that initiate the inflammatory response have not been adequately identified. Organ culture of full-thickness skin explants enables us to do so, because injury to the skin can be made in vitro, eliminating the rapid leakage of serum and infiltration of leukocytes that occur in vivo. In our studies, the military vesicant sulfur mustard (SM) (10 microliters of a 0.01 to 1.0% dilution) was topically applied to injure the epidermis of the explant. Then, the explants were cultured in small Petri dishes, usually for 18 h at 36 degrees C, and the organ-culture fluids were assayed for various inflammatory mediators. We found that the culture fluids from SM-exposed and control explants contained similar amounts of angiotensin-converting enzyme, trypsin-like and chymotrypsin-like proteases, acid phosphatase, beta-glucuronidase, beta-galactosidase, lysozyme, deoxyribonuclease, ribonuclease, interleukin 1, and lactic dehydrogenase. However, the culture fluids from SM-exposed explants contained increased amounts of histamine and plasminogen-activating activity, and often prostaglandin E2, when compared to culture fluids from control explants. After 3 to 4 d in culture, full-thickness human skin explants, when exposed to 0.2% SM (but not when exposed to 1.0% SM), sometimes showed separation of the epidermis and increased collagenase activity (i.e., hydroxyproline release). Thus, histamine (from local mast cells), and prostaglandin E2 and plasminogen-activating activity (probably from both mast cells and epidermal cells) are apparently involved in early mediation of the inflammatory response.

Published
1991
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