1. Solar Neutrinos, SNO, and SNOLAB
Art McDonald
For the SNO, SNO+ Collaborations
SNOW 2006,
Stockholm, Sweden
Ongoing physics motivation for solar neutrino measurements
Status of SNO, SNOLAB
Future solar neutrino experiments, SNO+

2. If neutrinos have mass:
Using the oscillation framework for neutrino flavor change:
If neutrinos have mass:
For three neutrinos:
Maki-Nakagawa-Sakata-Pontecorvo (MNSP) matrix
(Double b decay only)
Solar,Reactor
Atmos., Accel.
CP Violating Phase
Reactor, Accel
Majorana Phases
Range defined for Dm12, Dm23
For two neutrino oscillation in a vacuum: (valid approximation in many cases)

3. Matter Effects – the MSW effect
(Mikheyev, Smirnov, Wolfenstein)
The extra term arises because ne have an extra interaction
via W exchange with electrons in the Sun or Earth.
In the oscillation formula:
MSW effect can produce an energy spectrum distortion
and flavor regeneration in Earth giving a Day-night effect

4. solar neutrino physics with Hans Bethe and John Bahcall
Oscillations for Solar Neutrinos
Solar Model Flux Calculations
Bahcall et al. (2001)
, SNO
Matter Interaction Effect:LMA
CNO
Current Data for ne Survival
SAGE
GNO
Chlorine
SK,SNO
2005 was a sad year for
solar neutrino physics with
the passing of
Hans Bethe and John Bahcall pp
7Be
pep

5. Future solar neutrino measurements pp, 7Be, pep, 8B
Bahcall & Pena-Garay
hep-ph/
Vacuum
LMA
NEUTRINO PHYSICS
- Confirm matter effects (MSW).
- Improve Q12, Q13.
- Search for effects of sterile n,
Non-Standard Interactions,
Mass-varying neutrinos.
SOLAR PHYSICS
- Accurate measurement of
neutrino luminosity (pp, pep).
- Observe CNO neutrinos.
7Be
pep
Compare ES, CC
Compare ES, SSM

6. Unique Signatures in SNO (D2O)
Charged-Current (CC)
e+d  e-+p+p
Ethresh = 1.4 MeV
e only
Neutral-Current (NC)
x+d  x+n+p
Ethresh = 2.2 MeV
Equally sensitive to e nm t
3 ways to
detect neutrons
Elastic Scattering (ES)
x+e-  x+e-
x, but enhanced for e

7. Solar Neutrino Physics From SNO
Clear Evidence: Flavor change + active neutrino appearance
FCC ne
June 2001
(with SK)
3.3 s =
FES
ne (nm + nt)
FCC ne
5.3 s
April 2002 =
FNC
ne + nm + nt
Sept. 2003
March 2005
> 7 s
With salt
in SNO
Total 8B Solar Neutrino Flux Fx
FCC + (FES - FCC) x (1/0.15) =
June 2001
April 2002 Fx
Fnc =
~10%
Sept. 2003
March 2005

8. 3 neutron (NC) detection methods (systematically different)
Phase I (D2O)
Nov May 01
Phase II (salt)
July 01 - Sep. 03
Phase III (3He)
Nov. 04-Dec. 06
n captures on
2H(n, g)3H
Effc. ~14.4%
NC and CC separation by energy, radial, and directional distributions
2 t NaCl. n captures on
35Cl(n, g)36Cl
Effc. ~40%
NC and CC separation by event isotropy
40 proportional counters
3He(n, p)3H
Effc. ~ 30% capture
Measure NC rate with entirely different detection system.
36Cl
35Cl+n
8.6 MeV
5 cm 3H
2H+n
6.25 MeV n 3H p
3He
n + 3He  p + 3H

9. Data from Experiments in Operation
The latest SNO data: 391 live days with salt
hep-ex/ March 2005
New Information: Charged Current Energy Spectrum
Day-Night Asymmetry assuming ANC=0

10. CC, NC FLUXES MEASURED INDEPENDENTLY nm , nt Flavor change
determined by > 7 s.
CC, NC FLUXES
MEASURED
INDEPENDENTLY
nm , nt
The Total Flux of Active
Neutrinos is measured
independently (NC) and agrees
well with solar model
Calculations:
(Bahcall et al),
(Turck-Chieze et al)
Electron neutrinos
Improved accuracy
for q12.

11. Matter interaction (MSW) - SNO: CC/NC flux defines tan2 q < 1
SOLAR ONLY
AFTER NEW
SNO SALT
DATA
- The solar
results define the
mass hierarchy
(m2 > m1) through the
Matter interaction (MSW)
- SNO: CC/NC flux
defines tan2 q < 1
(ie Non - Maximal mixing)
by more than 5
standard deviations
Large mixing
Angle (LMA)
Region only
LMA for solar n predicts very small
spectral distortion, small (~ 3 %) day-night
asymmetry, as observed by SNO, SK
SOLAR PLUS
KAMLAND (assuming CPT)
(Reactor n’s)

12. Results from SNO -- Salt Phase
Oscillation Parameters,
2-D joint 1-s boundary
Marginalized 1-D 1-s
errors
SNO D2O D/N spectra
SNO Salt D/N spectra
KamLAND 766-day
SK-I zenith spectra
SAGE
Gallex/GNO
Cl/Ar

13. Periodicity in Solar Flux? SNO data 1999-2003
hep-ex/
Periodicity in Solar Flux?
SNO data
Unbinned Maximum Likelihood
Method compares fit for
Sinusoidal variation with
Expectation for zero amplitude.
Monte Carlo used to estimate
sensitivity shows
35% probability of a larger
likelihood ratio (S) with zero
sinusoidal amplitude than the
maximum S observed in the fits.
Conclusion: No observed
sinusoidal variation at periods
from 1 day to 10 years.
Analysis sensitive to amplitude
of 8-10% at 99% C.L..

14. Orbital Eccentricity SNO: hep-ex/0507079 SK: hep-ex/0508053
 = 0.021(3)
 = 0.014(9). Actual:
SNO: hep-ex/
SK: hep-ex/

15. Summary of SNO results
Direct observation (7 s) of neutrino flavor change via an appearance measurement:
Beyond the Standard Model for Elementary Particles.
Direct measurement (10 % accuracy) of total flux of active neutrinos: Strong confirmation of Solar Models.
The dominant transformation is to active neutrinos: Sterile neutrino fraction is restricted (<~ 13%).
Clear determination (5.3 s): q12 is non-maximal.
With other solar measurements: Strong evidence for Matter Enhancement in Sun (MSW – LMA solution).
With Kamland and CPT: Strong confirmation of neutrino oscillation due to finite mass (MNSP) as the primary physics explanation for appearance and disappearance measurements.

16. Present Phase: SNO Phase III
Neutral-Current Detectors (NCD):
An array of 3He proportional counters
40 strings on 1-m grid
~440 m total active length
Search for spectral distortion
Improve solar neutrino flux by breaking the CC and NC correlation ( = in Phase II):
CC: Cherenkov Signal  PMT Array
NC: n+3He  NCD Array
Improvement in 12, as
Correlations
D2O unconstrained
D2O constrained
Salt unconstrained
NCD
NC,CC
-0.950
-0.520
-0.521 ~0
CC,ES
-0.208
-0.162
-0.156
~-0.2
ES,NC
-0.297
-0.105
-0.064
Blind
Analysis
Phase III production data taking began Dec 2004; completion at the end of 2006

17. Production data and calibrations steadily since Nov. 2004
Neutral Current Detector Array deployed by a remotely operated submarine.
Production data and calibrations steadily since Nov. 2004

18. 252Cf neutrons b’s from 8Li g’s from 16N and t(p,g)4He
SNO Energy Calibrations: 25% of running time
6.13 MeV
19.8 MeV
Energy calibrated to ~1.5 %
Throughout detector volume
252Cf neutrons
+ AmBe, 24Na
b’s from 8Li
g’s from 16N and t(p,g)4He
Optical calibration at 5 wavelengths with the “Laserball”

19. The objective is for an improved CC/NC ratio measurement compared to the salt phase

20. SNO Physics Program Solar Neutrinos (5 papers to date)
Electron Neutrino Flux
Total Neutrino Flux
Electron Neutrino Energy Spectrum Distortion
Day/Night effects
hep neutrinos (paper in progress)
Periodic variations hep-ex/ [Variations < 8% (1 dy to 10 yrs)]
Atmospheric Neutrinos & Muons
Downward going cosmic muon flux
Atmospheric neutrinos: wide angular dependence [Look above horizon]
Supernova Watch (SNEWS)
Limit for Solar Electron Antineutrinos
hep-ex/
Nucleon decay (“Invisible” Modes: N nnn)
Phys.Rev.Lett. 92 (2004) [Improve limits by 1000]
Supernova Relic Electron Neutrinos

21. New International Underground Science Facility
At the Sudbury site: SNOLAB
- Underground Laboratory (2 km deep) ($ 38M): Complete mid- 2007
- Surface Laboratory ($ 10 M): Complete September, 2005
To pursue:
Future observations from a possible SNO+ detector
Solar Neutrinos
Geo - neutrinos
Supernova Neutrinos
Reactor Neutrinos
Dark Matter (WIMPS)
Measurements of nuclear recoils with ultra-low background
Double Beta Decay:
Are Neutrinos Majorana particles?
More accuracy for neutrino masses

22. The New SNOLAB
New
Excavation
To Date
SNO

23. Cosmic Ray
Muons Vs
Depth

24. Letters of Interest for SNOLAB Experiment Review Committee
Solar Neutrinos:
Liquid Ne: CLEAN (also Dark Matter)
Liquid Scintillator: SNO+ (also Double Beta Decay, Reactor Neutrinos, Geoneutrinos, Supernovae)
Liquid Helium (also Dark Matter)
Dark Matter:
Silicon Bolometers: CDMS
Liquid Xe: ZEPLIN, XENON
Gaseous Xe: DRIFT
Freon Super-saturated Gel: PICASSO
Timing of Liquid Argon Scintillation: DEAP
Neutrinoless Double Beta Decay:
Ge Crystals: Individual cryostats (MAJORANA) or Large Liquid Nitrogen bath
Liquid Xe: EXO
CdTe: COBRA
Recent Workshop and
Experiment Review Committee
Aug 14-16, 2005

25. Future low-energy solar  experiments* *
SNOLAB
Dan McKinsey Talk +
SNOLAB
* funded

26. SNO+ After heavy water is removed from SNO in 2007:
SNO plus liquid scintillator → physics program
pep and CNO low energy solar neutrinos (11C: 20 x < Gran Sasso)
SSM pep flux: uncertainty ±1.5%  allows precision test.
Comparison with the photon luminosity.
Tests the neutrino-matter interaction, sensitive to new physics.
non-standard interactions, mass-varying neutrinos, CPT violation,large 13, sterile neutrino admixture….
geo-neutrinos
240 km baseline reactor oscillation confirmation
supernova neutrinos
double beta decay (150Nd) ?

27. Survival Probability Rise
stat + syst + SSM errors estimated
SSM pep flux:
uncertainty ±1.5%
known source → precision test
Dm2 = 8.0 × 10−5 eV2
tan2q = 0.45
improves precision on q12
SNO CC/NC
sensitive to new physics:
non-standard interactions
solar density perturbations
mass-varying neutrinos
CPT violation
large q13
sterile neutrino admixture
Studying the rise confirms MSW or perhaps shows us new physics
pep n

28. de Holanda and Smirnov hep-ph/0307266
New Physics
NC non-standard Lagrangian
Friedland, Lunardini, Peña-Garay, hep-ph/
non-standard interactions
MSW is linear in GF and limits from n-scattering experiments  g2 aren’t that restrictive
mass-varying neutrinos
Miranda, Tórtola, Valle, hep-ph/
Sterile Neutrinos:
de Holanda and Smirnov hep-ph/
pep solar neutrinos are at
the “sweet spot” to test for new physics
Barger, Huber, Marfatia, hep-ph/

29. Event Rates (Oscillated)
resolution with
450 photoelectrons/MeV
7Be solar neutrinos
3600 pep/year/kton >0.8 MeV
using BS05(OP)
and best-fit LMA
2300 CNO/year/kton >0.8 MeV

30. 11C Cosmogenic Background
these plots from the KamLAND proposal
muon rate in KamLAND: 26,000 d−1 compared with
SNO: 70 d−1

31. KamLAND (7Be  phase) Elastic scattering: nx + e- → nx + e-
R&D work focus on reducing radioactive backgrounds in the liquid scintillator.
pep
238U
232Th
40K
85Kr
210Pb
(3.5 ± 0.5) x g/g
(5.2 ± 0.8) x g/g
< 2.7 x g/g
~ Bq/m3
~ g/g
10-16 g/g
10-18 g/g
~1 mBq/m3
~10-25 g/g
impurities present goal reduction OK
10-2
10-6
10-5
distillation purge
< 10-2
< 10-5
< 10-4
Kamland Purification System to be installed in 2006

32. Default Scintillator Identified
Like Ivory SNOW
Soap:
( /100) %
Pure.
It Floats!
Linear Alkyl Benzene (LAB) has the smallest scattering of all scintillating solvents investigated
LAB has the best acrylic compatibility of all solvents investigated
density r = 0.86 g/cm3:Hold down acrylic vessel.
…default is Petresa LAB with 4 g/L PPO, wavelength shifter mg/L bisMSB
because solvent is undiluted and SNO photocathode coverage is high, expect light output (photoelectrons/MeV) ~3× KamLAND

33. Geo-Neutrino Signal geo-n in SNO+
terrestrial antineutrino event rates:
Borexino: 10 events per year (280 tons of C9H12) / 29 events reactor
KamLAND: 29 events per year (1000 tons CH2) / 480 events reactor
SNO+: 64 events per year (1000 tons CH2) / 87 events reactor
based on Rothschild, Chen, Calaprice
Geophys. Res. Lett. 25, 1083 (1998)
KamLAND
geo-n in
SNO+
SNO+ geo-neutrinos and reactor background
KamLAND geo-neutrino
detection…July 28, 2005 in Nature

34. SNO++ (Nd Double Beta Decay)
0n: 1057 events per
year with 1% natural
Nd-loaded liquid
scintillator in SNO++.
Simulation
assuming light
output similar to
Kamland.
Very preliminary
simulation:
one year of data
mn = 0.15 eV

35. new collaborators welcome
SNO+ Collaboration
Queen’s
M. Chen*, M. Boulay, X. Dai, K. Graham, A. Hallin, C. Hearns, C. Kraus, C. Lan, J.R. Leslie, A. McDonald, V. Novikov, P. Skensved, A. Wright, U. Bissbort, S. Quirk
Laurentian
D. Hallman, C. Virtue
SNOLAB
B. Cleveland, R. Ford, I. Lawson
Brookhaven National Lab
A. Garnov, D. Hahn, M. Yeh
Los Alamos National Lab
A. Hime
LIP Lisbon
J. Maneira
potential collaborators from outside SNO (Italy, Germany, Russia) have indicated some interest
new collaborators welcome
A subset of the SNO collaboration will continue with SNO+
* Principal Investigator
We are working on a SNO+ proposal to be submitted this fall.

36. experiments as time permits
Some other fun SNOLAB
experiments as time permits

37. Letters of Interest for SNOLAB Experiment Review Committee
Solar Neutrinos:
Liquid Ne: CLEAN (also Dark Matter)
Liquid Scintillator: SNO+ (also Double Beta Decay, Reactor Neutrinos, Geoneutrinos, Supernovae)
Liquid Helium (also Dark Matter)
Dark Matter:
Silicon Bolometers: CDMS
Liquid Xe: ZEPLIN, XENON
Gaseous Xe: DRIFT
Freon Super-saturated Gel: PICASSO
Timing of Liquid Argon Scintillation: DEAP
Neutrinoless Double Beta Decay:
Ge Crystals: Individual cryostats (MAJORANA) or Large Liquid Nitrogen bath
Liquid Xe: EXO
CdTe: COBRA
Recent Workshop and
Experiment Review Committee
Aug 14-16, 2005

38. DEAP : Dark-matter Experiment with Argon PSD
scintillation pulse-shape analysis for discrimination of e- vs nuclear recoils
-> no electron-drift
DEAP : Dark-matter Experiment with Argon PSD

39. Background rejection with LAr (simulation) [Mark Boulay]
From simulation,
rejection > 108
@ 10 keV
(>>!)
108 simulated e-’s
100 simulated
WIMPs

40. Discrimination in liquid argon from DEAP-0
<pe> = 60
O(1in 105) consistent
with room
background
(preliminary)
preliminary
<pe> = 60 corresponds to 10 keV with 75% coverage
Final analysis and systematics evaluation being done

41. DEAP-0 DEAP- 1 (2 kg) Is under Construction at Queen’s. To be
Sited in SNOLAB
In 2006

42. Liquid Ar scintillation
Spin Independent Interaction
} Where we Are
Minimal Super-
Symmetric Models
} Some Future Expts.
Liquid Ar scintillation
M.G. Boulay & A. Hime, astro-ph/

43. Fluorine is very sensitive for the spin-dependent interaction
Montreal, Queen’s
Indiana, Pisa, BTI

44. SPIN - DEPENDENT
INTERACTION
20 g: hep-ex/
1 kg
2 kg to be run in 2006
10 kg
100 kg

45. Conclusions
The Sudbury Neutrino Observatory (SNO) has provided fundamental measurements of neutrino and solar properties.
Neutrino measurements have opened new areas of investigation for physics beyond the Standard Model of Elementary Particles.
With SNO, SNO+ and the deepest international underground site (SNOLAB) we have an exciting future for sensitive measurements of solar neutrinos, double beta decay and dark matter particles.

46. Another Canada – Sweden connection: Hockey
Mats Sundin

47. Congratulations to Sweden
Olympic Hockey Champions!