Final Results of the Sudbury Neutrino Observatory

The CAP'09 CongressMoncton, 7-10 June, 2009

Alain BelleriveOn behalf of the SNO CollaborationCarleton University, Ottawa, Canada

Final Results of the Sudbury Neutrino Observatory

The CAP'09 CongressMoncton, 7-10 June, 2009

Alain BelleriveOn behalf of the SNO CollaborationCarleton University, Ottawa, Canada

From Solving the Solar Neutrino Problem to Precision Physics

Outline Introduction

Solar Neutrino Flux (update)

The Sudbury Neutrino Observatory

The new stuff for 2011 (3-phase) !!!

New hep neutrino results

Expected 8B neutrinos survival probability

Constraints on Oscillation Parameters

Future Prospects

Rencontre de Blois May 29 – June 3, 2011 A.Bellerive

Evidence for Neutrino Mixing

Earth

Underground νe detector

Solarcore

Primary neutrino sourcep + p D + e+ + νe

Sun

~10 8 kilometers

Cosmic-rayshower

π0π+

µ+

νe

e+

νµ

νµ

Underground νe, νe, νµ, νµ

detector

Atmospheric neutrino sourceπ+ µ+ + νµ

e+ + νe + νµπ– µ– + νµ

e– + νe + νµ

~30 kilometers

30 meters

νe detectorNeutrinos νe, νµ, and νµ

Proton

beam

Pions

Copper beam stop

Muons and electrons

Watertarget

Solar Neutrinoslow energies

Atmospheric Neutrinoshigh energies

Beamstop Neutrinostunable energies

2 ≠eν

ν µ

First evidence of neutrino oscillation

Today’s talk !!!

Parallel Session Talk by Dr. Yoshihisa Obayashi

h

The First Piece

Solar Neutrino Flux and Physical Observables

The Sun produces υe in fusion nuclear reactions

Survival probability depends on the neutrino energy

Solar neutrino oscillation occurs inside the Sun

±1%

±6%

BPS08

±6% ±1.1%

±11%

±16%

Borexino

Neutrino Production in the Sun

Earth

Underground νe detector

Solarcore

Primary neutrino sourcep + p D + e+ + νe

Sun

~10 8 kilometers

Light Element Fusion Reactions

p + p →2H + e+ + νe

p + e- + p → 2H + νe

3He + p →4He + e+ + νe

7Be + e- →7Li + νe

99.75 %

0.25 %

15 %

~10-5 %

8B → 8Be* + e+ + νe 0.02 %

BPS08: (Bahcall) Pena‐Garay, C., & Serenelli, A. 2008. arXiv:0811.2424

http://www.sns.ias.edu/~jnb/

±1%

±6%

BPS08

±6% ±1.1%

±11%

±16%

Borexino

Neutrino Production in the Sun

Earth

Underground νe detector

Solarcore

Primary neutrino sourcep + p D + e+ + νe

Sun

~10 8 kilometers

Light Element Fusion Reactions

p + p →2H + e+ + νe

p + e- + p → 2H + νe

3He + p →4He + e+ + νe

7Be + e- →7Li + νe

99.75 %

0.25 %

15 %

~10-5 %

8B → 8Be* + e+ + νe 0.02 %

BPS08: (Bahcall) Pena‐Garay, C., & Serenelli, A. 2008. arXiv:0811.2424

http://www.sns.ias.edu/~jnb/

±1%

±6%

BPS08

±6% ±1.1%

±11%

±16%

Borexino

Neutrino Production in the Sun

Earth

Underground νe detector

Solarcore

Primary neutrino sourcep + p D + e+ + νe

Sun

~10 8 kilometers

Light Element Fusion Reactions

p + p →2H + e+ + νe

p + e- + p → 2H + νe

3He + p →4He + e+ + νe

7Be + e- →7Li + νe

99.75 %

0.25 %

15 %

~10-5 %

8B → 8Be* + e+ + νe 0.02 %

BPS08: (Bahcall) Pena‐Garay, C., & Serenelli, A. 2008. arXiv:0811.2424

http://www.sns.ias.edu/~jnb/

±1%

±6%

BPS08

±6% ±1.1%

±11%

±16%

Borexino

Neutrino Production in the Sun

Earth

Underground νe detector

Solarcore

Primary neutrino sourcep + p D + e+ + νe

Sun

~10 8 kilometers

Light Element Fusion Reactions

p + p →2H + e+ + νe

p + e- + p → 2H + νe

3He + p →4He + e+ + νe

7Be + e- →7Li + νe

99.75 %

0.25 %

15 %

~10-5 %

8B → 8Be* + e+ + νe 0.02 %

BPS08: (Bahcall) Pena‐Garay, C., & Serenelli, A. 2008. arXiv:0811.2424

http://www.sns.ias.edu/~jnb/

±1%

±6%

BPS08

±6% ±1.1%

±11%

±16%

Borexino

Neutrino Production in the Sun

Earth

Underground νe detector

Solarcore

Primary neutrino sourcep + p D + e+ + νe

Sun

~10 8 kilometers

Light Element Fusion Reactions

p + p →2H + e+ + νe

p + e- + p → 2H + νe

3He + p →4He + e+ + νe

7Be + e- →7Li + νe

99.75 %

0.25 %

15 %

~10-5 %

8B → 8Be* + e+ + νe 0.02 %

BPS08: (Bahcall) Pena‐Garay, C., & Serenelli, A. 2008. arXiv:0811.2424

http://www.sns.ias.edu/~jnb/

11

Sudbury Neutrino Observatory

FAAQ2006Alain Bellerive

υe

12

Solar Neutrino Mixing

quantity signed

21

22

212 mmm −=∆

mixingsolar 12 =θ

Survival Probability3 Parameters !

The state evolves with

time or distance

Pee ≡P(υe→υe)Pee = cos4(θ )[1-sin2(2θ )

sin2(ϕ)]Pee ≈ 1-sin2(2θ ) sin2(ϕ)where ϕ =1.27∆m2 L / E

Main Solar Physics:∆m2 & sin(2θ )

Experiment:Distance (L) & Energy (E)

1212

1213

12

12

small 13 =θ2-32

31 eV 10 2.3 ×±=∆m

The Second Piece:

Pre-SNO (~2001)

Solar Neutrino Problem (Pre SNO)

Experiment Medium Threshold (MeV)

Measured/SSM

Homestake Chlorine 0.814 0.34±0.03

SAGE+GALLEX/GNO Gallium 0.2332 0.52±0.03

SuperK H2O 7.0 0.406±0.013

Neutrino reactions

Source: arXiv:hep-ph/0406294

νe

~108 km

Measured PredictedPee

Phys.Rev. D64 (2001) 093007

LMA

Allowed Regions

SMA

LOW

VAC

JustSo2

∆m

2 (e

V2)

tan2θ

Combination of theChlorine, Gallium, SK, and CHOOZ

restricted the mixingparameters

Pre SNO (~2001) 212

2 mm ∆=∆

12 θθ = 013 =θ

TODAY

Mixing Parameters

Arranging the Pieces:

The Sudbury Neutrino Observatory

17

1700 tonnes InnerShield H2O

1000 tonnes D2O

5300 tonnes Outer Shield H2O

12 m Diameter Acrylic Vessel

Support Structure for 9500 PMTs, 60% coverage

Image courtesy National Geographic

Sudbury Neutrino

Observatory

6000 mwe overburden

17.8 m

Key signatures for ν mixing with SNO

18

τµ νννν

++=

ΦΦ

e

e

NC

CC

)(154.0 τµ νννν

++=

ΦΦ

e

e

ES

CC

Flavor change ? Pee(Eυ) ≠ 1 !CC

ES

NC

Timeline of SNO

Commissioning D2O + Salt D2O D2O + 3He counters

3He countersInstallCommission

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

D2O

Phase I Phase II Phase III

306days 391days 396days

PRL 87, 071301, 2001PRL 89, 011301, 2002PRL 89, 011302, 2002PRC 75, 045502, 2007

PRL 92, 181301, 2004PRC 72, 055502, 2005

Total of ~1100 live-days

PRL101, 111301, 2008

PRC, 055504, 2010

Upcoming… Phase I-II-III combined analysis

Combined Phase I-IILow Energy Threshold Analysis

DataAnalysis

Soon!

SNO Phases I+II Major Improvements Tune up the Monte Carlo on calibration data based on 5 years of

operational experience - Reduction of systematic uncertainties Improve optics (especially at large radii) with late light and new

energy estimator (improve energy resolution by 6%)

Energy ThresholdD2O phaseTeff = 5 → 3.5 MeVSalt phaseTeff = 5.5 → 3.5 MeV

Improve statistics CC by ~40% NC by ~70%

Allow to fit the background wall

Night

Day

Pee typical LMA

Eν

No distortion, no D/N:∆χ2 = 1.94 / 4 d.o.f.LMA-prediction:

∆χ2 = 3.90 / 4 d.o.f.

Previous global best-fit LMA point tan2θ12=0.468 ∆m2=7.59x10-5 eV2

DAY

NIGHTADN

Φ(8B) = 5.046in units of 106 cm−2 s−1

SNO Phases I+IIDirect joint-phase fit of Pee

PRC, 055504, 2010

Previous global best-fit LMA point tan2θ12=0.468 ∆m2=7.59x10-5 eV2

Previous global best-fit LMA point tan2θ12=0.468 ∆m2=7.59x10-5 eV2

+0.159 +0.107 -0.152 -0.123

SNO NCD’s Phase III

n

Ni wall

3He:CF4 gas

Cu wire19

1 ke

V

573

keV

764

keV

PRL101, 111301, 2008

Global View

Data Sets Solar Oscillation Analysis Radiochemical : Cl, Ga

– Ga rate: 66.1 ±3.1 SNU SAGE+GNO/GALLEX [PRC80, 015807(2009)]– Cl rate: 2.56 ±0.23 [Astrophys. J. 496 (1998) 505]

SK– SK-I 1496 days, zenith spectrum E ≥ 5.0 MeV– SK-II 791 days, spectrum + D/N E ≥ 7.5 MeV

Borexino– 7Be rate: 49 ± 5 cpd/100tons [PRL101, 091302(2008)]

SNO– Phase I + II (PMT Low Energy threshold E ≥ 4.0 MeV)– Phase III (NCD and PMT E ≥ 6.5MeV)

KamLAND reactor experiment: 2008 [PRL100, 221803 (2008)]

8B spectrum: W. T. Winter et al., PRC 73, 025503 (2006).

Oscillation Analyses: Global Solar

Best-fit LMA point:

tan2θ12 = 0.457 (+0.038 -0.041)

∆m2 = 5.89x10-5 eV2

(+2.13 -2.16)

Φ(8B) = 5.104in units of 106 cm−2 s−1

-2.95ΔΦ8B = +3.90 %

12

2ν model

Best-fit LMA point:

tan2θ12 = 0.457

θ12=34.06 deg

∆m2 = 7.59 x10-5 eV2

Solar + KamLAND 2-flavor

2ν model

-0.029+0.040

+0.20 -0.21

+1.16-0.84

-2.95ΔΦ8B = +2.37 %

Φ(8B) = 5.013in units of 106 cm−2 s−1

12

3ν model

Solar + KamLAND 3-flavor

Best-fit: sin2θ13=2.00 +2.09

-1.63 x10-2

sin2θ13 < 0.057 (95% C.L.)

Best-fit LMA point:

tan2θ12 = 0.468

∆m2 = 7.59 x10-5 eV2

-0.023+0.042

+0.21 -0.2112

Remark: SNO and SK global oscillation analyses consistent

28

Sudbury Neutrino Observatory

FAAQ2006Alain Bellerive

Newest stuff for summer 2011 !!!

SNO hep neutrino sensitivity (3-phase)

SSM

Preliminary fit to all SNO data

Φ(hep) < 21×103 ν/cm2/s (90% CL)

All phases combined D2O+Salt+NCD8B Pee(Eν) fit

SNO Full 3-Phase Expected improvement

Δχ2

Δχ2

Peeday

ADN

Conclusion & Future Great physics out of solar neutrino experiments

From solving SNP to precision physics Direct evidence of solar neutrino oscillation by SNO Global solar solution favors LMA (Cl+Ga+SK+BX+SNO)

SNO: 3-flavour analysis Upcoming new and final SNO I+II+III publication

Almost ready… to be expected for TAUP 2011 Expect further improvement with SNO 3-phase analysis

The only model-independent fit of solar survival probability

Rencontre de Blois May 29 – June 3, 2011 A.Bellerive

Merci !

Thank you!

Rencontre de Blois May 29 – June 3, 2011 A.Bellerive