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

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

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

Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003) Detecting at SNO NC xx    npd ES --    e e xx CC - epd  e p Low Statistics  ( e )  6  (  )  6  (  ) Strong directionality: Measurement of e energy spectrum Weak directionality: Measure total 8 B flux from the sun  e     

Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003) Phase I: Extracting the Solar Flux PDFs: kinetic energy T, event location R 3, and solar angle correlation cos  sun Max. Likelihood Fit OR +  CC NCES

Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003) See : Phys.Rev.Lett. 89 (2002) Phys.Rev.Lett. 89 (2002) Solar Model predictions are verified: [in 10 6 cm -2 s -1 ] Phase I: Missing Solar ’s Found 8 B  shape constrained fit: No 8 B  shape constraint: Null hypothesis of no flavor transformation rejected at 5.3 

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

Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003) Phase II (D 2 O + 2 tons NaCl) VariablesCC Stat. Error NC Stat. Error ES Stat. Error * E,R,  sun 3.4 %8.6%10% * R,  sun 9.5%24%11% E,R,  sun 4.2%6.3%10% E,R,  sun, Iso. 3.3%4.6%10% R,  sun,Iso. 3.8%5.3%10% * PRL, 89, No. 1, , (2002) Simulation Added 2 tons of salt in June 2001 to enhance NC detection efficiency and to improve the separability of NC and CC Cherenkov signals CC: Single electron (Cherenkov signal less isotropic) NC: Multiple  ’s following n capture on 35 Cl (Cherenkov signal more isotropic)

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

Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003) Phase II: Analysis & Challenges III. Neutron EfficiencyIV. 24 Na 23 Na (in the plumbing) activated by neutrons from the rock wall 24 Na  decays and emits 2  (1.37, 2.75 MeV) calibrated by controlled activation √(x 2 +y 2 ) [cm] Z [cm]

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

Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003) SNO Summary 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 II (D 2 O+NaCl) Phase III (Neutral Current Detector) All 3 He 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) The SNO Collaboration 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 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

The END

Backup Slides

Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003) Global Solar Analysis Inputs: 37 Cl, 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) 8 B floats free in fit, hep at 1 SSM SNO data only Global

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

Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003) Model Independent Test of MSW KamLAND establishes “LMA” region (  m 2 >10 -6 eV 2 ) Use CC/NC (solar model independent) to test for MSW effect in the Sun Fogli et al., hep-ph/ MSW offMSW On