SNO and the new SNOLAB SNO: Heavy Water Phase Complete Status of SNOLAB Future experiments at SNOLAB: (Dark Matter, Double beta, Solar, geo-, supernova ) Art McDonald, SNO Institute Director For the SNO Collaboration Neutrino Telescopes, Venice, 2007

Unique Signatures in SNO (D 2 O) Charged-Current (CC) e +d  e - +p+p E thresh = 1.4 MeV e only e only Elastic Scattering (ES) x +e -  x +e - x, but enhanced for e Neutral-Current (NC) x + d  x + n+p E thresh = 2.2 MeV Equally sensitive to e   3 ways to detect neutrons

Phase II (salt) July 01 - Sep. 03 Phase III ( 3 He) Nov Nov. 06 Phase I (D 2 O) Nov May 01 3 neutron (NC) detection methods (systematically different) n captures on 2 H(n,  ) 3 H Effc. ~14.4% NC and CC separation by energy, radial, and directional distributions 40 proportional counters 3 He(n, p) 3 H Effc. ~ 30% capture Measure NC rate with entirely different detection system. 2 t NaCl. n captures on 35 Cl(n,  ) 36 Cl Effc. ~40% NC and CC separation by event isotropy 36 Cl 35 Cl+n 8.6 MeV 3H3H 2 H+n 6.25 MeV n + 3 He  p + 3 H p 3H3H 5 cm n 3 He

Sudbury Neutrino Observatory 1700 tonnes Inner Shielding H 2 O 1000 tonnes D 2 O ($300 M) 5300 tonnes Outer Shield H 2 O 12 m Diameter Acrylic Vessel Support Structure for 9500 PMTs, 60% coverage Urylon Liner and Radon Seal 200 tonnes has been returned

ISOTROPY: NC, CC separation DIRECTION FROM SUN EVENTS VS VOLUME: Bkg < 10% ENERGY SPECTRUM FROM CC REACTION Heavy water SALT PHASE (“Near Background-free” analysis)

High accuracy for    Electron neutrinos   The Total Flux of Active Neutrinos is measured independently (NC) and agrees well with solar model Calculations: (BPS07), (Turck-Chieze et al 04) CC, NC FLUXES MEASURED INDEPENDENTLY Flavor change determined by > 7  Implies Matter Interactions (Folgi, Lisi 2004)

- SNO: CC/NC flux defines tan 2    < 1 (ie Non - Maximal mixing) by more than 5 standard deviations. -The mass hierarchy is defined (m 2 > m 1 ) through the matter interaction (MSW) SOLAR ONLY AFTER NEW SNO SALT DATA SOLAR PLUS KAMLAND (assuming CPT) (Reactor ’s) Large mixing Angle (LMA) Region: MSW LMA for solar predicts very small spectral distortion, small (~ 3 %) day-night asymmetry, as observed by SNO, SK

Final Phase: SNO Phase III 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+ 3 He  NCD Array Improvement in  12, as Neutral-Current Detectors (NCD): An array of 3 He proportional counters 40 strings on 1-m grid ~440 m total active length Phase III production data taking began Dec 2004; completed November 2006 CorrelationsD 2 O unconstrained D 2 O constrained Salt unconstrained NCD NC,CC ~0 CC,ES ~-0.2 ES,NC ~0 Blind Analysis Total Radioactivity similar To Phase I, II

Another analysis is almost complete that combines data from the first two SNO Phases and reduces the threshold by ~ 1 MeV. This also provides improved accuracy on CC/NC flux ratio. BLIND ANALYSIS: Add in unknown number of neutrons from muons

New International Underground Science Facility At the Sudbury site: SNOLAB - Underground Laboratory (2 km deep) ($ 38M) funded: Complete end Surface Laboratory ($ 10 M) funded: Complete September, Cryopit addition underground: Funding support nearly completed ($ 14 M) Excavation to be completed in early 2008 (Cavity capable of housing 100 tons of liquid cryogen, with an independent path for venting gas to the surface in case of accident.) - Total additional excavated volume in new lab: 2 times SNO volume. To pursue Experiments that benefit from a very deep and clean lab: Direct Observation of Dark Matter (WIMPS) via nuclear recoil Neutrino-less Double Beta Decay Low Energy Solar Neutrinos Particle physics and solar physics Geo – neutrinos Supernova Neutrinos Reactor Neutrinos

The New SNOLAB SNO To Be Ready for Experiments: to 400 times lower  fluxes than Gran Sasso, Kamioka. New Excavation To Date 2/3 All Lab Air: Class < 2000 Cryopit

Total Muon Flux vs Depth Relative to Flat Overburden D. Mei, A. Hime astro-ph/ Canfranc 2.5 km.w.e. Frejus 4.8 km.w.e.

Control Rooms Meeting Rooms Clean Room Laboratories Surface Facilities

Letters of Interest for SNOLAB Dark Matter: Timing of Liquid Argon/Neon Scintillation: DEAP/CLEAN (1 Tonne) Freon Super-saturated Gel: PICASSO Silicon Bolometers: SUPER-CDMS Liquid Xe: ZEPLIN- III, LUX (1 Tonne) Gaseous Xe: DRIFT Neutrino-less Double Beta Decay: 150 Nd: Organo-metallic in liquid scintillator in SNO+ 76 Ge: MAJORANA or next generation GERDA/MAJORANA 136 Xe: EXO (Gas or Liquid) CdTe: COBRA Solar Neutrinos: Liquid Scintillator: SNO+ (also Reactor Neutrinos, Geo-neutrinos) Liquid Ne: CLEAN (also Dark Matter) SuperNovae: HALO: Pb plus SNO 3 He detectors; SNO+ 5 th Workshop and Experiment Review Committee Aug 21, 22,

SNO tonnes Inner Shielding H 2 O Replace Heavy water with 1000 tonnes Liquid Scintillator 5300 tonnes Outer Shield H 2 O 12 m Diameter Acrylic Vessel Support Structure for 9500 PMTs, 60% coverage Urylon Liner and Radon Seal

Best Scintillator Identified Linear Alkyl Benzene (LAB) has the smallest scattering of all scintillating solvents investigated and the best acrylic compatibility. density  = 0.86 g/cm 3 : Ropes to hold down acrylic vessel. …default is Petresa LAB with 4 g/L PPO, wavelength shifter mg/L bisMSB because LAB solvent is undiluted and SNO photocathode coverage is high, expect light output (photoelectrons/MeV) ~3× KamLAND Nd metallic-organic compound has been demonstrated to have long attenuation lengths, stable for more than a year. 0.1 % of Nd can be added with little degradation of light output.

150 Nd 3.37 MeV endpoint (9.7 ± 0.7 ± 1.0) × yr 2  half-life (NEMO-III) isotopic abundance 5.6% (in SNO+ 0.1% loading=56 kg) Nd is one of the most favorable double beta decay candidates with large phase space due to high endpoint. table from F. Avignone Neutrino 2004 Neutrino-less Double Beta Decay Candidate

0 : 1057 events per year with 500 kg 150 Nd-loaded liquid scintillator in SNO+. Simulation assuming light output and background similar to Kamland. SNO+ ( 150 Nd Neutrino-less Double Beta Decay) One year of data m  = 0.15 eV Super-Nemo and SNO+ seek use of Laser Isotope Separation facility in France to enrich 100’s of kg of 150 Nd isotope. CEA has agreed to initial study during 07/08 U Chain Th Chain

Test the MSW Energy Dependence, transition from MSW ( 8 B) to vacuum osc. (pp). Look for: - Non-standard interactions - Mass-varying neutrinos Friedland, Lunardini, Peña-Garay, hep-ph/ Barger, Huber, Marfatia, hep-ph/ The pep solar neutrinos are at a sensitive energy to test for new physics. The pep (and CNO) can be observed at SNO+ depth with no 11 C interference. pep solar NC non-standard Lagrangian Miranda, Tórtola, Valle, hep-ph/ SNO+ (Liquid Scintillator)

Assuming U, Th as achieved at Kamland, Bi, K set at Kamland objectives, Max Likelihood fit extracts pep at +- 4%. Negligible background from 11 C at this depth. 3 Years of Data pep CNO

Other Double Beta Decay Example: Majorana 60 to 120 kg enriched 86% 76 Ge many crystals, each segmented advanced signal processing require special low background materials deep, clean underground location Few keV resolution at Q  = 2039 keV known technology sensitivity to few years m <~ 0.1 eV US, Canada, Japan, Russia collaboration MOU for future consideration of >~ 500 kg experiment with GERDA

EXO: Liquid or Gas (~ 200 kg enriched 136 Xe at present) Liquid Compact detector No pressure vessel Small shield -> lower purity reqd. Gas Energy resolution  Tracking & multi-site rejection In-situ Ba tagging Large Cryostat Poorer energy, tracking resolution Ex-situ Ba tagging Large detector Needs very large shield Pressure vessel is massive (Carleton, Laurentian, SNOLAB, TRIUMF development work) EXO-200: Expected sensitivity < 0.35 eV EXO-200 Liquid Detector with scintillation and ionization measurement: To Be Deployed at WIPP in June (No Ba tagging) Independent development of Laser-tagging of single Barium atoms in liquid. EXO-Gas: Wire chamber under development in parallel Future – much larger mass.

DEAP/CLEAN: 1 Tonne Fiducial Liquid Argon From simulation,  rejection > keV 10 8 simulated e-’s 100 simulated WIMPs M.G. Boulay & A. Hime, astro-ph/ DARK MATTER - Scintillation time spectrum for Ar enables WIMP recoils to be separated from gammas from 39 Ar background. - Simulation indicates that 39 Ar and other gamma-beta backgrounds can be discriminated from WIMPS using only scintillation light for up to 1 tonne fiducial Volume of liquid argon. - DEAP and CLEAN collaborations have come together to build this new detector with a simple and easily scaled technology at SNOLAB.

Discrimination in liquid argon from DEAP-0 (<1 kg) O(1in 10 5 ) consistent with room neutrons in surface lab. = 60 corresponds to 10 keV threshold with 75% coverage = 60 DEAP- 1 (7 kg) Is in operation on surface. To be sited in SNOLAB in May Will test Discrimination to 10 9

- 3.5 Tonnes of pure liquid Argon (Neon) in an 85-cm spherical acrylic vessel, viewed by 200 cold PMT’s through acrylic light guides. Very high light collection, external H 2 O shield. - Objective: 1 tonne liquid central fiducial volume to eliminate surface radioactivity and obtain sensitivity to WIMP cross sections down to cm 2. (1000 times better than present limits for spin-independent cross section). - SNOLAB depth removes neutrons from cosmic rays. Residual backgrounds are only few per year. - Argon with reduced 39 Ar is also under investigation. - $ 3 M of $ 5 M total funding available soon. - Planned deployment during 2009, operation in DEAP/CLEAN Detector

For Example: Muon-induced Neutron Background for a CDMS-type Dark Matter Experiment: Mei and Hime: astro-ph/

Spin Independent Interaction } Where we Are } Future Expts. Minimal Super- Symmetric Models DEAP/CLEAN Super-CDMS LUX cm 2

Cryogenic Dark Matter Search: CDMS

Planned start of construction: 2008 assuming funding approval soon.

ZEPLIN-III 8 kg Xe Liquid – gas Scintillation + Electroluminescence Ready for Immediate Deployment

Montreal, Queen’s Indiana, Pisa, BTI Fluorine is very sensitive for the spin-dependent interaction WIMP-Nucleus Spin-Dependent Interaction

SPIN - DEPENDENT INTERACTION 1 kg 10 kg 100 kg 20 g: hep-ex/ kg being run in PICASSO

SNO Cavern: 2008: SNO+ SNO Utility Rm: Now: PICASSO-IB (2kg) Ladder Labs: 2 of 2008: Super-CDMS 2009: PICASSO IIB 2009: EXO-200-Gas 2009: Majorana (TBD) SNO Control Rm: 2007: DEAP-1 South Drift: 2008: ZEPLIN-III Cube Hall:1 (or 2) of 2008: DEAP/CLEAN 2009: PICASSO-III 2009: LUX (1 ton Xe) Cryopit: 1 of 2008: DEAP/CLEAN 2009: LUX Future??:Large EXO, CLEAN, 1-ton GERDA/MAJORANA 2008:HALO Initial Suite of Experiments

Summary SNO is analyzing data from its three phases and will be providing new publications in the near future with improved accuracy. Underground measurements have opened new areas of investigation for physics beyond the Standard Model of Elementary Particles and astrophysical topics. With a very deep, clean international underground facility (SNOLAB) we have an exciting future for sensitive measurements of solar neutrinos, neutrino-less double beta decay and dark matter particles.