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

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

Fréjus Underground Laboratory : 4800 m.w.e. The NEMO3 detector 3 m 4 m B (25 G) 20 sectors Fréjus Underground Laboratory : 4800 m.w.e. 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) 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 Able to identify e-, e+, g and a Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi 06-11 June 2005

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

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

Start taking data 14 February 2003 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

bb decay isotopes in NEMO-3 detector bb2n measurement 116Cd 405 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 130Te 454 g Qbb = 2529 keV External bkg measurement 100Mo 6.914 kg Qbb = 3034 keV 82Se 0.932 kg Qbb = 2995 keV natTe 491 g Cu 621 g bb0n search (All the enriched isotopes produced in Russia) Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi 06-11 June 2005

bb events selection in NEMO-3 Deposited energy: E1+E2= 2088 keV Internal hypothesis: (Dt)mes –(Dt)theo = 0.22 ns Common vertex: (Dvertex) = 2.1 mm Vertex emission (Dvertex)// = 5.7 mm Transverse view Longitudinal view Run Number: 2040 Event Number: 9732 Date: 2003-03-20 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 Drift distance Scintillator + PMT Trigger: 1 PMT > 150 keV 3 Geiger hits (2 neighbour layers + 1) Trigger rate = 7 Hz bb events: 1 event every 1.5 minutes Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi 06-11 June 2005

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

Expected Performance of the detector Time Of Flight: Time Resolution (bb channel)  250 ps at 1 MeV ToF (external crossing e- ) > 3 ns external crossing e- totaly rejected External Background bb events from the foil (Dtmes – Dtcalc) external hypo. (ns) (Dtmes – Dtcalc) internal hypo. (ns) Calorimeter: 97% of the PMTs+scintillators are ON Energy Resolution: calibration runs (every ~ 40 days) with 207Bi sources 17% 14% FWHM (1 MeV) Int. Wall 3" PMTs Ext. Wall 5" PMTs 207Bi 2 conversion e- 482 keV and 976 keV 482 keV 976 keV FWHM = 135 keV (13.8%) Daily Laser Survey to control gain stability of each PM gamma: efficiency ~ 50 % @ 500 keV, Ethr = 30 keV 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 b- DVertex DVertex = distance between the two vertex Expected Performance of the detector has been reached Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi 06-11 June 2005

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

100Mo 22 preliminary results (Data 14 Feb. 2003 – 22 Sep. 2004) Sum Energy Spectrum Angular Distribution NEMO-3 219 000 events 6914 g 389 days S/B = 40 NEMO-3 219 000 events, S/B =40 6914 g, 389 days 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

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-3 405 g 168.4 days 1371 events S/B = 7.5 NEMO-3 37 g 168.4 days 449 events S/B = 2.8 NEMO-3 5.3 g 168.4 days 72 events S/B = 0.9 116Cd 150Nd 96Zr Data Data Data 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

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

bb0n Analysis: Background Measurement NEMO-3 can measure each component of its background ! External Background 208Tl (PMTs) Measured with (e-, g) external events ~ 10-3 bb0n-like events year-1 kg -1 with 2.8<E1+ E2<3.2 MeV External Neutrons 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 background suppressed by a factor 10 in Dec. 2004 with a radon-free air purification system 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

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

Limit on Majoron and on V+A (limits @ 90% CL) 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) 10-6 l < 3.2 10-6 Tomoda (1991), Suhonen (1994) Tomoda (1991)

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

Radon-free air factory Activity: A(222Rn) < 1 mBq/m3 !!! 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

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

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 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 Nuclear Matrice Elements Ref: Simkovic (1999), Stoica (2001), Suhonen (1998,2003), Rodin (2005), Caurier (1996)

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

The SUPERNEMO project Idea : continue with a tracko-calo like detector with a mass of few 100 kg of 82Se (T 1/2 bb2n ~ 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

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

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

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

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

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

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

MOON : tracking with scintillating fibres with 100Mo Other projects 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

SuperNEMO is a large scale bb0n detector 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 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 SuperNEMO is a large scale bb0n detector Need an international collaboration: France, Russia, UK, Tchec., Japan and USA !