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Status of the Sudbury Neutrino Observatory (SNO)

Status of the Sudbury Neutrino Observatory (SNO). Alan Poon for the SNO Collaboration Institute for Nuclear and Particle Astrophysics Lawrence Berkeley National Laboratory, Berkeley, USA. Outline. What we did…( Phase I: Pure D 2 O target ) What we are doing…( Phase II: D 2 O + NaCl )

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Status of the Sudbury Neutrino Observatory (SNO)

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  1. Status of the Sudbury Neutrino Observatory (SNO) Alan Poon for the SNO Collaboration Institute for Nuclear and Particle Astrophysics Lawrence Berkeley National Laboratory, Berkeley, USA

  2. Outline • What we did…(Phase I: Pure D2O target) • What we are doing…(Phase II: D2O + NaCl) • What we will be doing…(Phase III: Neutral Current Detectors) Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)

  3. Sudbury Neutrino Observatory 2 km to surface 1006 tonnes D2O 17.8m dia. PMT Support Structure 9456 20-cm dia. PMTs 56% coverage 12.01m dia. acrylic vessel 1700 tonnes of inner shielding H2O Urylon liner 5300 tonnes of outer shielding H2O Nucl. Inst. Meth. A449, 127 (2000) Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)

  4. Detecting  at SNO p n +  + + - CC d p e e n +  + + n NC d p n x x ES - - +  + n e n e x x • Measurement ofneenergy spectrum • Weak directionality: • Measure total 8Bnflux from the sun • s(ne) = s(nm) = s(nt) • Low Statistics • s(ne)  6 s(nm)  6 s(nt) • Strong directionality: Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)

  5. Phase I: Extracting the Solar n Flux OR + Df CC NC ES Max. Likelihood Fit • PDFs: • kinetic energyT, event location R3, • and solar angle correlation cosqsun Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)

  6. Phase I: Missing Solar n’s Found Null hypothesis of no flavor transformation rejected at 5.3s See : Phys.Rev.Lett. 89 (2002) 011301 Phys.Rev.Lett. 89 (2002) 011302 Solar Model predictions are verified: [in 106 cm-2 s-1] 8Bn shape constrained fit: No 8Bn shape constraint: Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)

  7. Correlation in Signal Extraction (Phase I) Strong statistical anti-correlation between NC and CC in the signal extraction Correlation Matrix Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)

  8. Phase II (D2O + 2 tons NaCl) • Added 2 tons of salt in June 2001 to enhance NC detection efficiencyandto improve the separability of NC and CC Cherenkov signals • CC: Single electron • (Cherenkov signal less isotropic) • NC: Multiple g’s following n capture on 35Cl • (Cherenkov signal more isotropic) Simulation * PRL, 89, No. 1, 011301, (2002) Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)

  9. Phase II: Blind Analysis • ~ 280 live days • Triple blind analysis to ensure independence from Phase I • CC, ES: • data set pre-scaled by an “unknown” factor of 80±10% • NC: • Leak an “unknown” number of spallation neutrons in the data • NC interaction cross section in the Monte Carlo is spoiled by an • “unknown” factor Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)

  10. Phase II: Analysis & Challenges I. Energy Scale Drift II. Light Isotropy Absolute Energy Scale Uncertainty ~1.1% (preliminary) [c.f. 1.2% in Phase I] Mott scattering missing in EGS4, now added in the SNO Monte Carlo Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)

  11. Phase II: Analysis & Challenges III. Neutron Efficiency IV. 24Na • 23Na (in the plumbing) activated by neutrons from the rock wall • 24Na b decays and emits 2 g (1.37, 2.75 MeV) • calibrated by controlled activation Z [cm] √(x2+y2) [cm] √(x2+y2) [cm] Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)

  12. Decoupling CC and NC in Phase III • CC: Cherenkov Signal  PMT Array • NC: n+3He  Neutral Current Detector Array Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)

  13. SNO Summary Phase II (D2O+NaCl) • Final full detector calibration of Phase II completed • Analysis of the blind data is complete…box to be opened upon completion of internal review • Other analyses in progress: solar anti-neutrino, day-night flux, proton decay, atmospheric neutrinos, muon spallation…Stay tuned! Phase III (Neutral Current Detector) • All 3He counters have been constructed and stored in the underground lab • All counters are being characterized • Integration of electronics and DAQ in progress • Deployment in Fall 2003 Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)

  14. The SNO Collaboration J.D.Anglin, M.Bercovitch, W.F.Davidson, R.S.Storey* National Research Council of Canada J.C.Barton, S.Biller, R.A.Black, R.J.Boardman, M.G.Bowler, J.Cameron, B.T.Cleveland, X.Dai, G.Doucas, J.A.Dunmore, A.P.Ferarris, H.Fergani, K.Frame, N.Gagnon, H.Heron, N.A.Jelley, A.B.Knox, M.Lay, W.Locke, J.Lyon, S.Majerus, G.McGregor, M.Moorhead, M.Omori, C.J.Sims, N.W.Tanner, R.K.Taplin, M.Thorman, P.M.Thornewell, P.T.Trent, N.West, J.R.Wilson University of Oxford E.W.Beier, D.F.Cowen, M.Dunford, E.D.Frank, W.Frati, W.J.Heintzelman, P.T.Keener, J.R.Klein, C.C.M.Kyba, N.McCauley, D.S.McDonald, M.S.Neubauer, F.M.Newcomer, S.M.Oser, V.L Rusu, R.Van Berg, P.Wittich University of Pennsylvania R.Kouzes Princeton University E.Bonvin, M.Chen, E.T.H.Clifford, F.A.Duncan, E.D.Earle, H.C.Evans, G.T.Ewan, R.J.Ford, K.Graham, A.L.Hallin, W.B.Handler, P.J.Harvey, J.D.Hepburn, C.Jillings, H.W.Lee, J.R.Leslie, H.B.Mak, J.Maneira, A.B.McDonald, B.A.Moffat, T.J.Radcliffe, B.C.Robertson, P.Skensved Queen’s University D.L.Wark Rutherford Appleton Laboratory, University of Sussex R.L.Helmer, A.J.Noble TRIUMF Q.R.Ahmad, M.C.Browne, T.V.Bullard, G.A.Cox, P.J.Doe, C.A.Duba, S.R.Elliott, J.A.Formaggio, J.V.Germani, A.A.Hamian, R.Hazama, K.M.Heeger, K.Kazkaz, J.Manor, R.Meijer Drees, J.L.Orrell, R.G.H.Robertson, K.K.Schaffer, M.W.E.Smith, T.D.Steiger, L.C.Stonehill, J.F.Wilkerson University of Washington G.Milton, B.Sur Atomic Energy of Canada Ltd., Chalk River Laboratories S.Gil, J.Heise, R.J.Komar, T.Kutter, C.W.Nally, H.S.Ng, Y.I.Tserkovnyak, C.E.Waltham University of British Columbia J.Boger, R.L Hahn, J.K.Rowley, M.Yeh Brookhaven National Laboratory R.C.Allen, G.Bühler,H.H.Chen* University of California, Irvine I.Blevis, F.Dalnoki-Veress, D.R.Grant, C.K.Hargrove, I.Levine, K.McFarlane, C.Mifflin, V.M.Novikov, M.O'Neill, M.Shatkay, D.Sinclair, N.Starinsky Carleton University T.C.Anderson, P.Jagam, J.Law, I.T.Lawson, R.W.Ollerhead, J.J.Simpson, N.Tagg, J.-X.Wang University of Guelph J.Bigu, J.H.M.Cowan, J.Farine, E.D.Hallman, R.U.Haq, J.Hewett, J.G.Hykawy, G.Jonkmans, S.Luoma, A.Roberge, E.Saettler, M.H.Schwendener, H.Seifert, R.Tafirout, C.J.Virtue Laurentian University Y.D.Chan, X.Chen, M.C.P.Isaac, K.T.Lesko, A.D.Marino, E.B.Norman, C.E.Okada, A.W.P.Poon, S.S.E Rosendahl, A.Schülke, A.R.Smith, R.G.Stokstad Lawrence Berkeley National Laboratory M.G.Boulay, T.J.Bowles, S.J.Brice, M.R.Dragowsky, M.M.Fowler, A.S.Hamer, A.Hime, G.G.Miller, R.G.Van de Water, J.B.Wilhelmy, J.M.Wouters Los Alamos National Laboratory Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)

  15. The END

  16. Backup Slides

  17. Global Solar n Analysis • Inputs: • 37Cl, latest Gallex/GNO, new SAGE, SK 1258-day day & night spectra • SNO day spectrum (total: CC+NC+ES+background) • SNO night spectrum (total: CC+NC+ES+background) • 8B floats free in fit, hep n at 1 SSM Global SNO data only Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)

  18. What will SNO and KamLAND tell us in the future de Holanda et al., hep-ph/0212270 Barger et al., hep-ph/0204253 Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)

  19. Model Independent Test of MSW • KamLAND establishes “LMA” region (Dm2>10-6 eV2) • Use CC/NC (solar model independent) to test for MSW effect in the Sun MSW On MSW off Fogli et al., hep-ph/0211414 Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)

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