1 Where do we find SNO in April? Hamish Robertson Kubodera Festschrift April, 2004

2 Sudbury Neutrino Observatory 1700 tonnes Inner Shielding H 2 O 1000 tonnes D 2 O 5300 tonnes Outer Shield H 2 O 12 m Diameter Acrylic Vessel Support Structure for 9500 PMTs, 60% coverage Urylon Liner and Radon Seal

3 Heavy Water from Bruce Plant

4 Reactions in SNO NC xx    npd ES --    e e xx -Low Statistics -Mainly sensitive to e,, some -sensitivity to  and  -Strong direction sensitivity -Gives e energy spectrum well -Weak direction sensitivity  1-1/3cos(  ) - e only. -Measure total 8 B flux from the sun. - Equal cross section for all types CC - epd  e p

5 Neutrino-deuteron interactions Effective Field Theory EFT (pionless) Standard Nuclear Physics Approach (SNPA): Potential model Higher-order corrections with mesons,  ’s Precision numerical calculation Expansion of interactions in power series. Scattering length a, deuteron binding , momentum p are all small compared to pion mass  (lowest non-nucleonic excitation) K. Kubodera: NSGK, PRC63, (2001) NSA+, NP A707, 561 (2002) Butler, Chen, Kong: BCK, PRC 63, (2001)

6 EFT gives general results Leading order & NLO cross sections model-independent Cross sections are analytic expressions All observable parameters (doubly differential cross sections, angular distributions, neutrino and antineutrino, CC & NC) First undetermined term is in NNLO. Term is the weak axial two-body current, called L 1,A Depend on L 1A

7 L1A can be fit to SNPA calculations A SINGLE choice of L 1A produces this agreement! EFT SNPA

8 EFT compared to Standard Nuclear Physics Approach Ratio of Butler et al. (BCK) EFT with L 1A = 4.0 fm 3 to Nakamura et al. (NSA+) CC NC MeV EFT/SNPA

9 Neutrino Flavor Composition of 8 B Flux Fluxes (10 6 cm -2 s -1 ) e : 1.76(11)  : 3.41(66) total : 5.09(64) SSM : 5.05 PRL 89, , 2002 Shape-constrained fits. Pure D 2 O data. BP04: 5.79 (1  0.23)

10 L 1A = 4.0 L 1A = 20 ES

11 ProcessL 1A (fm 3 )Reference CC, NC, ES 4.0  6.3 Chen et al., PRC 67, (2003), nucl-th/ Reactor antineutrinos 3.6  4.6 Butler et al. nucl- th/ Tritium  decay 4.2  0.1 Schiavilla et al. PRC 58, 1263 (1998); Park et al. nucl-th/ & nucl-th/ ; Ando et al. nucl- th/ Solar pp reaction 4.8  5.9 Brown et al. nucl- th/ Potential model 4.0Nakamura et al. NP A707, 561 (2002) Determinations of L 1A

12 Total spectrum (NC + CC + ES)

13 Less than Maximal Mixing at 3  Best Fit  m 2 = 6.2 x eV 2 tan 2  = 0.40 Flux/SSM =  Bounds  m 2 < 3.3 x tan 2  < 0.80 tan 2  m 1 SOLAR LMA de Holanda and Smirnov hep-ph/

14 tan 2  12 -  m 12 2 Solar OnlySolar+KL rateSolar+KL spect. de Holanda & Smirnov, hep-ph/ , hep-ph/

15 Advantages of NaCl for Neutron Detection Higher capture cross section Higher energy release Many gammas n 36 Cl * 35 Cl 36 Cl  3H3H 2 H+n 35 Cl+n 6.0 MeV 8.6 MeV  = b  = 44 b

16 Neutron Capture Efficiency in SNO 35 Cl(n,  ) 36 Cl Average Eff. = T e ≥ 5.5 MeV and R  ≤ 550 cm 2 H(n,  ) 3 H Average Eff. = T e ≥ 5.0 MeV and R  ≤ 550 cm Radial Position of 252 Cf Source, cm

17 Cherenkov light and  14 ) 43 o Charged particle, v > c/n Hollow cone of emitted photons Energy & Direction  ij      

18 Use of  14 to distinguish neutrons and e -

19 Addition of Mott scattering to EGS4 Angular Distribution of 5 MeV electrons after passing through ~1 mm of water

20 Blind Analysis Three blindfolds for the analysts: Include unknown fraction of neutrons that follow muons Spoil the NC cross section in MC Veto an unknown fraction of candidate events

21  14 Distributions for SNO Salt Data Data from July 26, 2001 to Oct. 10, live days 3055 candidate events: CC NC ES

22 Sun-angle distributions Toward sun Away from sun

23 Energy spectra Electron kinetic energy

Radioassay Bottom of vessel 2/3 way up Top of vessel MnOx HTiO MnOx HTiO

25 Salt Phase: “Box” Opened Aug. 13, 2003 Shape of 8 B spectrum in CC and ES not constrained: Standard (Ortiz et al.) shape of 8 B spectrum in CC and ES: Pure D2O Phase Salt Phase

26 tan 2  12 -  m 12 2 before Salt Phase Solar OnlySolar+KL rateSolar+KL spect. de Holanda & Smirnov, hep-ph/ , hep-ph/

27 From the Salt Phase… Ratio:

28 Closing in on  m 2,  --90% --95% --99% % LMA I only at > 99% CL

29 Results from SNO -- Salt Phase Oscillation Parameters, 2-D joint 1-  boundary Marginalized 1-D 1-  errors LMA II rejected at >99% CL Maximal mixing rejected at 5.4  A paper plus a “companion” guide can be found at sno.phy.queensu.ca Accepted (at last!) by PRL; nucl-ex/

30 Mass (eV) =0 Neutrino Masses and Flavor Content 3 e mu tau Atmospheric 2 1 Solar Atmospheric 2 1 Solar = ??

31  neutrino masses: < m 1 +m 2 +m 3 < 6.6 eV  Laboratory limit on fraction of universe closure density: Large-scale structure limit : Cosmological Implications Atmospheric neutrinos:  m 23 2  2.0  eV 2  One neutrino mass > 0.04 eV SNO + KamLAND:  m 12 2  7.1 x eV 2  One neutrino mass > eV Limits on “ e mass” give: m( 1,2,3 ) < 2.2 eV <  < 0.13  < 0.02

32 B. Cabrera, 2004

33 Physics Motivation Improved NC, NC/CC:  12 CC spectral shape: MSW,  m 2 Detection Principle 2 H + x  p + n + x MeV (NC) 3 He + n  p + 3 H MeV Event-by-event separation.. Different systematic uncertainties than neutron capture on NaCl. Measure neutrons separately: CC shape x n 40 Strings on 1-m grid 398 m total active length NCD PMT SNO Phase III (NCD Phase)- Begins ‘04  3 He Proportional Counters (“NC Detectors”)

34 Why Event-by-Event? Analyst: A. Hime

Breaking the Correlation J. Manor, M. Smith

39 Weld and Leak Check System Two NCD segments held by inflatable cuffs. Cuffs cast from approved silicone resin. NCD holders insert into rotary stroke bearings. Rotation of both NCDs locked by mechanical linkage with orbit motor. Vertical position with 3 state cam and fine screw. Laser head can rotate and follow NCD eccentricity. Rotate NCD or rotate laser weld head. Side port for making NCD wire connection, He injection and sniffing.

40 Lowering a welded string and its electrical cable

41 Flying the ROV to the string’s anchor position.

42

43 Installed 3 He Counter Strings N 3 He 4 He

44

45 Spectrum of 3 He(n,p) 3 H in K6 string Channel Counts per channel 764 keV AmBe Source Jan. 13, 2004

46 Where do we find SNO in April? Salt phase of SNO now complete. Another 150 days of data being analyzed. Spectral shape, day/night this summer. Neutral-current detectors installed, checkout in progress. Production running with NCDs expected by summer. Run with D2O until Dec. 31, Improved precision on  12,  13, sterile neutrinos, hep, matter- enhancement effects…

The SNO Collaboration T. Kutter, C.W. Nally, S.M. Oser, C.E. Waltham University of British Columbia J. Boger, R.L. Hahn, R. Lange, M. Yeh Brookhaven National Laboratory A.Bellerive, X. Dai, F. Dalnoki-Veress, R.S. Dosanjh, D.R. Grant, C.K. Hargrove, R.J. Hemingway, I. Levine, C. Mifflin, E. Rollin, O. Simard, D. Sinclair, N. Starinsky, G. Tesic, D. Waller Carleton University P. Jagam, H. Labranche, J. Law, I.T. Lawson, B.G. Nickel, R.W. Ollerhead, J.J. Simpson University of Guelph J. Farine, F. Fleurot, E.D. Hallman, S. Luoma, M.H. Schwendener, R. Tafirout, C.J. Virtue Laurentian University Y.D. Chan, X. Chen, K.M. Heeger, K.T. Lesko, A.D. Marino, E.B. Norman, C.E. Okada, A.W.P. Poon, S.S.E. Rosendahl, R.G. Stokstad Lawrence Berkeley National Laboratory M.G. Boulay, T.J. Bowles, S.J. Brice, M.R. Dragowsky, S.R. Elliott, M.M. Fowler, A.S. Hamer, J. Heise, A. Hime, G.G. Miller, R.G. Van de Water, J.B. Wilhelmy, J.M. Wouters Los Alamos National Laboratory S.D. Biller, M.G. Bowler, B.T. Cleveland, G. Doucas, J.A. Dunmore, H. Fergani, K. Frame, N.A. Jelley, S. Majerus, G. McGregor, S.J.M. Peeters, C.J. Sims, M. Thorman, H. Wan Chan Tseung, N. West, J.R. Wilson, K. Zuber Oxford University E.W. Beier, M. Dunford, W.J. Heintzelman, C.C.M. Kyba, N. McCauley, V.L. Rusu, R. Van Berg University of Pennsylvania S.N. Ahmed, M. Chen, F.A. Duncan, E.D. Earle, B.G. Fulsom, H.C. Evans, G.T. Ewan, K. Graham, A.L. Hallin, W.B. Handler, P.J. Harvey, M.S. Kos, A.V. Krumins, J.R. Leslie, R. MacLellan, H.B. Mak, J. Maneira, A.B. McDonald, B.A. Moffat, A.J. Noble, C.V. Ouellet, B.C. Robertson, P. Skensved, M. Thomas, Y.Takeuchi Queen’s University D.L. Wark Rutherford Laboratory and University of Sussex R.L. Helmer TRIUMF A.E. Anthony, J.C. Hall, J.R. Klein University of Texas at Austin T.V. Bullard, G.A. Cox, P.J. Doe, C.A. Duba, J.A. Formaggio, N. Gagnon, R. Hazama, M.A. Howe, S. McGee, K.K.S. Miknaitis, N.S. Oblath, J.L. Orrell, R.G.H. Robertson, M.W.E. Smith, L.C. Stonehill, B.L. Wall, J.F. Wilkerson University of Washington

48 Total Active 8 B Fluxes In units of Bahcall, Pinsonneault, Basu SSM, 5.05 x 10 6 cm -2 s -1 BPB01 SSM Junghans et al. nucl-ex/ ± 0.16 SNO D20 (constrained) 1.01 ± 0.13 SNO Salt (unconstrained) 1.03 ± 0.09

49 Time after muon, s Counts per second N. Oblath

50 16 N in D 2 O Counts per s A.D. Marino

51 ( ,n) Reactions

52 BOREXINO: radiopurity requirements ~ 70  Bq / m 3 in PC (0.3ev/day/100tons) ~ 10Bq / m 3 in air 222 Rn 0.16  Bq/m 3 (0.5  Bq/m 3 ) in N events/day/ton 1.1Bq/m 3 (13mBq/m 3 ) in air 85 Kr, ( 39 Ar) < g/g(PC)~ 1ppm in dustK nat ~ g/g(PC)~ 1ppm in dust ~ 1ppb stainless steel ~ 1ppt IV nylon 238 U, 232 Th 14 C/ 12 C~ C/ 12 C< C Borexino levelTypical Conc. If secular equilibrium is broken: contaminants such as 210 Pb, 210 Po may be a serious problem

53 CC, ES, and NC fluxes from Pure D 2 O Phase Shape of 8 B spectrum in CC and ES not constrained: Standard (Ortiz et al.) shape of 8 B spectrum in CC and ES:

54 Salt Phase: “Box” Opened Aug. 13, 2003 Shape of 8 B spectrum in CC and ES not constrained: Standard (Ortiz et al.) shape of 8 B spectrum in CC and ES: