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NEMO-3 Experiment N eutrino E ttore M ajorana O bservatory RESULTS OF NEMO3 & SUPERNEMO

NEMO-3 Experiment N eutrino E ttore M ajorana O bservatory RESULTS OF NEMO3 & SUPERNEMO. Laurent Simard 1 for the NEMO-3 Collaboration CENBG , IN2P3-CNRS et Université de Bordeaux, France Charles University , Praha, Czech Republic CTU , Praha, Czech Republic

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NEMO-3 Experiment N eutrino E ttore M ajorana O bservatory RESULTS OF NEMO3 & SUPERNEMO

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  1. NEMO-3 Experiment Neutrino Ettore Majorana Observatory RESULTS OF NEMO3 & SUPERNEMO Laurent Simard 1 for the NEMO-3 Collaboration CENBG, IN2P3-CNRS et Université de Bordeaux, France Charles University, Praha, Czech Republic CTU, Praha, Czech Republic FES University, Morocco INEEL, Idaho Falls, USA IReS, IN2P3-CNRS et Université de Strasbourg, France ITEP, Moscou, Russia JINR, Dubna, Russia Jyvaskyla University, Finland Kharkov University, Ukrain 1 LAL, IN2P3-CNRS et Université Paris-Sud, France LSCE, CNRS Gif sur Yvette, France LPC, IN2P3-CNRS et Université de Caen, France Manchester University, United Kingdom Mount Holyoke College, USA University of Osaka, Japan RRC Kurchatov Institute, Moscow, Russia Saga University, Saga, Japan University of Texas, USA UCL, London, United Kingdom Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi 06-11 June 2005

  2. Plan of the talk: • Results of NEMO-3 experiment • NEMO-3 Detector • Measurement of bb2n decay for several nuclei • Search for bb0n decay with 100Mo and 82Se Description of future projects • The SUPERNEMO project • other projects

  3. 20 sectors B(25 G) 3 m Magnetic field: 25 Gauss Gamma shield: Pure Iron (e = 18 cm) Neutron shield: 30 cm water (ext. wall) 40 cm wood (top and bottom) (since march 2004: water + boron) 4 m Able to identify e-, e+, g and a The NEMO3 detector Fréjus Underground Laboratory : 4800 m.w.e. Source: 10 kg of  isotopes cylindrical, S = 20 m2, e ~ 60 mg/cm2 Tracking detector: drift wire chamber operating in Geiger mode (6180 cells) Gas: He + 4% ethyl alcohol + 1% Ar + 0.1% H2O Calorimeter: 1940 plastic scintillators coupled to low radioactivity PMTs Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi 06-11 June 2005

  4. Cathodic rings Wire chamber PMTs Calibration tube scintillators bb isotope foils Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi 06-11 June 2005

  5. AUGUST 2001 Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi 06-11 June 2005

  6. NEMO-3 Opening Day, July 2002 Start taking data 14 February 2003 Water tank wood coil Iron shield Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi 06-11 June 2005

  7. bb2n measurement bb0n search bb decay isotopes in NEMO-3 detector 116Cd405 g Qbb = 2805 keV 96Zr 9.4 g Qbb = 3350 keV 150Nd 37.0 g Qbb = 3367 keV 48Ca 7.0 g Qbb = 4272 keV 130Te454 g Qbb = 2529 keV External bkg measurement natTe491 g 100Mo6.914 kg Qbb = 3034 keV 82Se0.932 kg Qbb = 2995 keV Cu621 g (All the enriched isotopes produced in Russia) Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi 06-11 June 2005

  8. Transverse view Run Number: 2040 Event Number: 9732 Date: 2003-03-20 Longitudinal view Vertex emission Vertex emission Drift distance Deposited energy: E1+E2= 2088 keV Internal hypothesis: (Dt)mes –(Dt)theo = 0.22 ns Common vertex: (Dvertex) = 2.1 mm (Dvertex)// = 5.7 mm • Trigger: 1 PMT > 150 keV • 3 Geiger hits (2 neighbour layers + 1) • Trigger rate = 7 Hz • bb events: 1 event every 1.5 minutes Criteria to select bb events: • 2 tracks with charge < 0 • 2 PMT, each > 200 keV • PMT-Track association • Common vertex • Internal hypothesis (external event rejection) • No other isolated PMT (g rejection) • No delayed track (214Bi rejection) bb events selection in NEMO-3 Typical bb2n event observed from 100Mo Transverse view Run Number: 2040 Event Number: 9732 Date: 2003-03-20 Longitudinal view 100Mo foil 100Mo foil Geiger plasma longitudinal propagation Scintillator + PMT Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi 06-11 June 2005

  9. e+ – e- pair eventB rejection 2e-event e-Neventto measure l  -  (delay track) event 214Bi 214Po 210Pb

  10. Calorimeter: • 97% of the PMTs+scintillators are ON • Energy Resolution: calibration runs (every ~ 40 days) with 207Bi sources bb events from the foil Ext. Wall 5" PMTs Int. Wall 3" PMTs Tracking Detector: • 99.5 % Geiger cells ON • Vertex resolution: 2 e- channels (482 and 976 keV) using 207Bi sources at 3 well known positions in each sector • s (DVertex) = 0.6 cm • s// (DVertex) = 1.3 cm(Z=0) • e+/e- separation with a magnetic field of 25 G ~ 3% confusion at 1 MeV FWHM (1 MeV) 14% 17% b- External Background • Daily Laser Survey to control gain stability of each PM • gamma: efficiency ~ 50 % @ 500 keV, Ethr = 30 keV DVertex 976 keV • Time Of Flight: • Time Resolution (bb channel)  250 ps at 1 MeV ToF (external crossing e- ) > 3 ns external crossing e- totaly rejected b- 207Bi 2 conversion e- 482 keV and 976 keV Expected Performance of the detector has been reached DVertex = distance between the two vertex FWHM = 135 keV (13.8%) (Dtmes – Dtcalc) internal hypo. (ns) (Dtmes – Dtcalc) external hypo. (ns) 482 keV Performance of the detector Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi 06-11 June 2005

  11. Measurement of 2b2n decay in NEMO-3 Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi 06-11 June 2005

  12. 100Mo 22 preliminary results (Data 14 Feb. 2003 – 22 Sep. 2004) Sum Energy Spectrum Angular Distribution 219 000 events, S/B =40 6914 g, 389 days NEMO-3 219 000 events 6914 g 389 days S/B = 40 NEMO-3 100Mo 100Mo • Data 22 Monte Carlo • Data Background subtracted 22 Monte Carlo Background subtracted 7.37 kg.y T1/2 = 7.11± 0.02 (stat) ± 0.54 (syst)  1018 y Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi 06-11 June 2005

  13. Data Data Data 22 preliminary results for other nuclei NEMO-3 932 g 241.5 days 2385 events S/B = 3.3 Background subtracted 82Se 82Se T1/2 = 9.6± 0.3 (stat) ± 1.0 (syst)  1019 y 116Cd T1/2 = 2.8 ± 0.1 (stat) ± 0.3 (syst)  1019 y 150Nd T1/2 = 9.7 ± 0.7 (stat) ± 1.0 (syst)  1018 y 96Zr T1/2 = 2.0 ± 0.3 (stat) ± 0.2 (syst)  1019 y NEMO-3 NEMO-3 NEMO-3 37 g 168.4 days 449 events S/B = 2.8 405 g 168.4 days 1371 events S/B = 7.5 5.3 g 168.4 days 72 events S/B = 0.9 96Zr 150Nd 116Cd bb2n simulation bb2n simulation bb2n simulation E1+E2 (MeV) E1+E2 (MeV) E1+E2 (MeV) Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi 06-11 June 2005

  14. Search for 2b0n decay in NEMO-3 Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi 06-11 June 2005

  15. Radon background suppressed by a factor 10 in Dec. 2004 with a radon-free air purification system bb0n Analysis: Background Measurement NEMO-3 can measure each component of its background ! External Background 208Tl (PMTs) Measured with (e-, g) external events ~ 10-3bb0n-like events year-1 kg -1 with 2.8<E1+ E2<3.2 MeV ExternalNeutrons and High Energy gamma Measured with crossing e- or (e-,e+)int events with E1+E2> 4 MeV  0.05 bb0n-like events year-1 kg -1 with 2.8<E1+ E2<3.2 MeV 208Tl impurities inside the foils ~ 60 mBq/kg Measured with (e-,2g), (e-,3g) events coming from the foil ~ 0.06 bb0n-like events year-1 kg -1 with 2.8<E1+ E2<3.2 MeV Radon inside NEMO-3 detector Measured with (e-,g,a) events from the gas or the foil ~ 1 bb0n-like events year-1 kg -1 with 2.8<E1+ E2<3.2 MeV 100Mo bb2n decay T1/2 = 7.14 1018 y ~ 0.3 bb0n-like events year-1 kg -1 with 2.8<E1+E2<3.2 MeV

  16. 100Mo (6.914 kg) T1/2(bb0n) > 4.6 1023 y mn < 0.66 – 2.81 eV 82Se (0.932 kg) T1/2(bb0n) > 1.0 1023 y mn < 1.75 – 4.86 eV Cu+natTe+130Te In agreement with only Radon bkg expected 100Mo 82Se [2.8-3.2] MeV: e(bb0n) = 8 % Expected bkg = 8.1 ± 1.3 Nobserved = 7 events [2.7-3.2] MeV: e(bb0n) = 13 % Expected bkg = 3.1 ± 0.6 Nobserved = 5 events Previous limits: T1/2(bb0n) > 5.5 1022 y Ejiri et al. (2001) Previous limits: T1/2(bb0n) > 9.5 1021 y Arnold et al. (1992) Nuclear Matrice Elements Ref: Simkovic (1999), Stoica (2001), Suhonen (1998,2003), Rodin (2005), Caurier (1996) Limit on the effective mass of the Majorana neutrino Phase 1 (Feb. 2003 – Sept. 2004: 1.08 y of data) with radon bkg (limits @ 90% CL)

  17. Limit on Majoron and on V+A (limits @ 90% CL) Limit on Majoron 100Mo: T1/2 (bb0nM) > 1.8 1022 y 82Se: T1/2 (bb0nM) > 1.5 1022 y gM < (5.3 – 8.5) 10-5 (best limit) gM < (0.7 – 1.6) 10-4 Simkovic (1999), Stoica (1999)Simkovic (1999), Stoica (2001) • Limit on V+A • 100Mo: T1/2 (bb0n V+A) > 2.3 1023 y 82Se: T1/2 (bb0n V+A) > 1.0 1023 y • l < (1.5 – 2.0) 10-6l < 3.2 10-6 • Tomoda (1991), Suhonen (1994) Tomoda (1991)

  18. Free-Radon Purification System in construction Radon was the dominant background for NEMO-3 Today: A(222Rn) in the LSM ~ 15 Bq/m3 Factor ~ 10 too high May 2004 :Tent surrounding the detector May 2004 August 2004 : Radon-free SuperKamiokande-like Air Factory Expected activity: A(222Rn) ~ 0.2 Bq/m3 150 m3/h 2 x 450 kg charcoal @ -40oC Expected Purification Factor ~ 75 Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi 06-11 June 2005

  19. Radon-free air factory Starts running on October 2004 the 4th In Laboratoire Souterrain de Modane 2 x 450 kg charcoal @ -50oC, 7 bars Activity: A(222Rn) < 1 mBq/m3 !!! Flux: 125 m3/h

  20. 0 17 40 Time (days) After installation of radon-free air factory (active charcoal) 222Rn Activity between february 2003 and september 2004 ~ 0.95 Bq now ~ 0.1 Bq (réduction by a factor ~ 10) Only 0.7 evt/y of background for bb0n of 100Mo < Nbdf due to bb2n

  21. in 2009 after 5 years of data 6914 g of 100Mo T1/2() 2 1024 y (90% C.L.) m < 0.32 – 1.35 eV 932 g of 82Se T1/2() 8 .1023 y (90% C.L.) m < 0.62 – 1.72 eV NEMO-3 Expected sensitivity Background • External Background: negligible • Internal Background: 208Tl: 60 Bq/kg for 100Mo 300 Bq/kg for 82Se 214Bi : < 300 Bq/kg ~ 0.1 count kg1 y 1 with 2.8<E1+E2<3.2 MeV • 100Mo T1/2 = 7.14 1018 y ~ 0.3 count kg1 y 1 with 2.8<E1+E2<3.2 MeV Nuclear Matrice Elements Ref: Simkovic (1999), Stoica (2001), Suhonen (1998,2003), Rodin (2005), Caurier (1996)

  22. CONCLUSIONS ON NEMO3 • NEMO-3 Detector running since 14 Feb. 2003 Expected performance of the detector has been reached ! • 2b2n preliminary results for 100Mo, 82Se, 96Zr, 116Cd and 150Nd already more than 235 000 2b2n events collected 100Mo: in favour of Single State Dominance (SSD) 100Mo bb2n decay to excited state has been measured with ~ 4 s • Preliminary T1/2(bb0n) limit (1.08 years of data): • 100Mo (4.10 kg.y) T1/2(bb0n) > 4.6 1023 y mn < 0.7 – 2.8 eV • 82Se (0.55 kg.y) T1/2(bb0n) > 1023 y mn < 1.8 – 4.9 eV • Level of backgounds as excepted Free radon purification system in operation in August 2004 Reduction of the radon level by a factor ~10 • Expected sensitivity in 5 years after radon purification • 100Mo: T1/2(bb0n) > 2 .1024 y <mn> < 0.32 – 1.35 eV • 82Se: T1/2(bb0n) > 8 1023 y <mn> < 0.62 – 1.72 eV Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi 06-11 June 2005

  23. The SUPERNEMO project Idea : continue with a tracko-calo like detector with a mass of few 100 kg of 82Se (T 1/2bb2n ~ 15 times greater than for 100Mo, Q bb around 3 MeV also) 3 years R&D program Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi 06-11 June 2005

  24. NEMO-3 SuperNEMO 7 kg 100Mo T1/2(bb2n) = 7. 1018 y Mass of isotope 100 kg 82Se T1/2(bb2n) = 1020 y T1/2(bb0n) > 2. 1024 y <mn> < 0.3 – 1.3 eV Sensitivity T1/2(bb0n) > 2. 1026 y <mn> < 40 – 110 meV 214Bi < 300 mBq/kg 208Tl < 20mBq/kg Internal contaminations in the source foils in 208Tl and 214Bi 214Bi < 10 mBq/kg 208Tl < 2mBq/kg FWHM ~ 7% at 3 MeV (dominated by source foil) FWHM ~ 12% at 3 MeV (dominated by calorimeter ~ 8%) Energy resolution e(bb0n) = 8 % poor energy resolution e- backscattering on scintillator e(bb0n) ~ 40 % Efficiency bb2n + (208Tl,214Bi) ≤ 1 cts/ 100 kg /y bb2n ~ 2 cts / 7 kg / y (208Tl, 214Bi) ~ 0.5 cts/ 7 kg /y Background From NEMO-3 to SuperNEMO

  25. SuperNEMO preliminary design Side view Plane and Modular Geometry (~5 kg of enriched isotope/module) 1 Module: Source (40 mg/cm2) 4 x 3 m2 Tracking volume: drift wire chamber in Geiger mode, ~ 3000 cells Calorimeter: scintillators + PMTs (~1000 PMTs) 20 modules: 100 kg of enriched isotope ~ 60 000 channels for drift chamber ~ 20 000 PMT if scint. block ~ 2 000 PMT if scint. bars 4 m 1 m 5 m Top view

  26. 1,5m 1,5m Water shield Need of cavity of ~ 60m x 15m x15m Possible in Gran Sasso or in Modane if a new cavity

  27. sources R&D GOAL : A(214Bi) < ~ 10 mBq/kg A(208Tl) < ~2 mBq/kg not only enrich and purify sources, but also measure their radiopurity 2 mBq/kg of 1 kg of sources give 64 decays/year !!! sensitivity in 208Tl of High Purity-Germanium detectors used for the measurement of NEMO3 sources : 60 mBq/kg

  28. Idea : stay with plastic scintillators (to keep time of flight) but improve resolution One option : reduce thickness of scintillator to collect more photons produced by scintillation and separate tagging of gfrom the energy measurement of the e- optimisation of the shape of the scintillator (small bloc, long bar read by several PMTs…) collaboration CEN Bordeaux Gradignan-LAL-Kharkov-Dubna already promising results In addition : some english groups working on inorganic scintillators Need to improve also the performances of photomultiplier : scintillator adapted to PMTs, improve quantum efficiency collaboration CEN Bordeaux Gradignan-Photonis calorimetry R&D Goal : reach FWHM less than 4% at 3 MeV (for NEMO-3 8%) 6% (source) (+) 4 % (calo) ~ 7 % (global)

  29. CUORE bolometer 130Te GERDA HP-diode 76Ge 741 kg of natural Tellurium, 10 y Phase I : 15kg.y b=10-1/(keV.kg.y) T ½ (bb0n) > 3 1025 y mee < 0.23-0.75 eV b=10-2/(keV.kg.y) R = 10 keV T ½ (bb0n) > 2.1 1026 y mee < 0.02-0.1 eV b=10-3/(keV.kg.y) R = 5 keV T ½ (bb0n) > 9.2 1026 y mee < 0.01-0.05 eV Phase II : 100kg.y b=10-3/(keV.kg.y) T ½ (bb0n) > 2 1026 y mee < 0.09-0.29 eV Other projects

  30. EXO : TPC with liquid 136Xe, tagging of the decay product by bb0n (barium ion) with a laser 10 tons, they already have prototype of 200 kg of xenon (80% of 136Xe) b=0.015 c/(keV.kg.y) T ½ (bb0n) > 2 1026 y mee < 0.39-1.2 eV MAJORANA : segmented diodes of HP-Ge 500 kg of 86% 76Ge, 10 y T ½ (bb0n) > 4 1027 y mee < 0.038 0.007 eV MOON : tracking with scintillating fibres with 100Mo Other projects

  31. R&D program 2005-2007 in order to reach T1/2(bb0n) > 2. 1026 y  <mn> < 40 – 110 meV • DE/E < 7% (FWHM) @ 3 MeV =  (DE/E sources)2 + (DE/E calorimeter)2 • e(bb0n) ~ 40% • 208Tl < 2 mBq/kg and 214Bi < 10 mBq/kg Conclusions • If any bb0n signal seen in any isotope, it will HAVE to be observed by a tracko-calo detector « a la NEMO » to tag the 2 e- emitted in bb0n decay • NEMO-3 reached the expected performance and nominal background data taking will continue up to 2009 expected sensitivity: T1/2(bb0n) > 2. 1024 with 7 kg of 100Mo • T1/2(bb0n) > 8. 1023 with 1 kg of 82Se • NEMO technique can be extrapolated to 100 kg SuperNEMO is a large scale bb0n detector Need an international collaboration: France, Russia, UK, Tchec., Japan and USA !

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