Transcript Status of the Sudbury Neutrino Observatory (SNO) Alan Poon for the SNO Collaboration

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 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)
2 km to surface
Sudbury Neutrino Observatory
17.8m dia. PMT Support Structure
9456 20-cm dia. PMTs
56% coverage
1006 tonnes
D2O
12.01m dia. acrylic vessel
1700 tonnes of inner shielding H2O
Urylon
liner
5300 tonnes of outer shielding H2O
Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)
Nucl. Inst. Meth. A449, 127 (2000)
Detecting  at SNO
CC
 e + d  p + p + e-
• Measurement of e energy spectrum
• Weak directionality: 1 0.340 cos 
NC
 x + d  p + n + x
• Measure total 8B  flux from the sun
• s(e) = s(m) = s(t)
ES
x + e-  x + e -
• Low Statistics
• s(e)  6 s(m)  6 s(t)
• Strong directionality: e  18
(Te = 10 MeV)
Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)
Phase I: Extracting the Solar  Flux
CC
NC
ES
 Signals
Radioactive
Backgrounds
Amplitudes Free Amplitudes Fixed
Perturb
Observables:
R, u , T

Shift amplitudes
(±1 s)
Max.
Likelihood Fit
 CC  NC  ES
OR
• PDFs:
kinetic energy T, event location R3,
and solar angle correlation cos sun
Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)

 e mt
+
D
Phase I: Missing Solar ’s Found
CC ( e ) =  e
 NC ( x ) =  e +  mt
 ES ( x ) =  e + 0.15 mt


+0.05
+0.09
e = 1.76 0.05
(stat.)
(syst.) 10 6 cm2s 1
0.09
+0.45
+0.48
 mt = 3.410.45
(stat.)
(syst.) 10 6 cm2s 1
0.45
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]
8B
 shape constrained fit:
No
8B
 shape constraint:

Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)
+1.01
SSM (BP01) = 5.05 0.81
+0.44
+0.46
constrained
SNO
= 5.09
unconstrained
SNO
+1.57
+0.55
= 6.42
(stat.)
(sy st.)
1.57
0.58
0.43
(stat.)
0.43
(sy st.)
Correlation in Signal Extraction (Phase I)
Strong statistical anti-correlation between NC and CC in the
signal extraction
constrained = 5.09 +0.44 (stat.) +0.46 (sy st.)
SNO
0.43
0.43
+1.57
+0.55
unconstrained
SNO
= 6.42
(stat.)
(sy st.)
1.57
0.58

Correlation Matrix
Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)
CC
ES
NC
CC
1.000
-0.162
-0.520
ES
-0.162
1.000
-0.105
NC
-0.520
-0.105
1.000
Phase II (D2O + 2 tons NaCl)
• 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 g’s following n capture on 35Cl
(Cherenkov signal more isotropic)
CC
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, 011301, (2002)
Simulation
Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)
Variables
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]
Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)
II. Light Isotropy
Mott scattering missing in EGS4,
now added in the SNO Monte Carlo
Phase II: Analysis & Challenges
IV. 24Na
III. Neutron Efficiency
• 23Na (in the plumbing)
activated by neutrons from
the rock wall
• 24Na b decays and emits 2
g (1.37, 2.75 MeV)
Z [cm]
• calibrated by controlled
activation
√(x2+y2) [cm]
Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)
√(x2+y2) [cm]
Decoupling CC and NC in Phase III
• CC: Cherenkov Signal  PMT Array
• NC: n+3He  Neutral Current Detector Array
Phase I
Source
Energy Scale ¶
Energy Resolution ¶
Energy Non-linearity ¶
Vertex Resolution ¶
Vertex Accuracy
Angular Resolution
Internal Source p-d ¶
External Source p-d ¶
D2O Cherenkov ¶
H2O Cherenkov
AV Cherenkov
PMT Cherenkov ¶
Neutron Capture
 Systematic
 Statistical
 Uncertainties
¶ CC NC anti-correlation
Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)
DNC/NC (%)
-6.2, +6.1
-0.0, +4.4
±0.4
±0.1
±1.8
-0.3, +0.3
-1.5, +1.6
-1.0, +1.0
-2.6, +1.2
-0.2, +0.4
-0.2, +0.2
-2.1, +1.6
-4.0, +3.6
-8.5, +9.1
-8.5, +8.6
12
Phase III
Projected
DNC/NC (%)
~0
~0
~0
0.0
0.0
0.0
3.0
1.0
0.0
0.0
0.0
0.0
3.0
4.5
4
6
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)
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
Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)
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
Global Solar  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  at 1 SSM
SNO data only
Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)
Global
What will SNO and KamLAND tell us in the future
Alan Poon, EPS HEP 2003, Aachen, Germany (July 2003)
de Holanda et al., hep-ph/0212270
Barger et al., hep-ph/0204253
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)