1. Yuri Shitov Imperial College London On behalf of the NEMO Collaboration A search for neutrinoless double beta decay: from NEMO-3 to SuperNEMO Moriond EW 2010, 6-13.03.2010 Outline:  Physics of double beta decay  Latest results from NEMO-3 experiment  Status of the SuperNEMO project  Summary of world status in the field  Conclusion

2. Double beta decay basic statements (A,Z)  (A,Z+2) + 2e - + 2 (A,Z)  (A,Z+2) + 2e -  2 : allowed SM process, T 1/2 ~ 10 20 y  0 : beyond the SM, T 1/2  10 25 y Other scenarios (Majoron emission, Right- handed (V+A) current, SUSY, etc.) are possible Light neutrino exchange Experimental patterns (E 1 +E 2 )/Q 

3. where: T   : half-life of the process : effective neutrino Majorana mass M   : Nuclear matrix element (NME) G   : phase space factor Double beta decay basic formulas THEORY where: M : source mass ε : efficiency W : molecular weight t : time of measurement a : Isotope abundance or enrichment N BGR : background events ΔE: energy resolution EXPERIMENT

4.  and neutrino fundamental properties Probe of neutrino nature. Neutrinos are Majorana fermions (particle  antiparticle) if  0 takes place  See-Saw mechanism, Leptogenesis, Baryon asymmetry, CP violation Neutrino mass hierarchy.  0 measurements might help to establish the right one. Absolute mass scale.  0 experiments are among the most sensitive ones. Spreads are due to variations of unknown CP phases

5. Experimental techniques to observe  -decay  -daughter rate E1+E2 spectrum E1, E2,  Larger mass Better resolution High (~ 100%) efficiency Real  -observation. Any  -source can be measured Potentially zero-background Test of  mechanisms There is no “ideal” method to meet all requirements! Geochemical & Radiochemical Calorimetric Source  detector Tracking + Calorimetric TPC Time Projection Chamber

6. Claim of  observation 4.2  evidence of  in 76 Ge(Q  =2039 keV) has been claimed by Klapdor-Kleingrothaus group (KGC) analyzing data of Heidelberg-Moscow (HM) experiment: Exposure: 71 kg  y (1995-2003) T 1/2  =1.5  10 25 y =0.2-0.45 eV A.M. Bakalyarov et al. Part. and Nucl., Lett. 125, 21 (2005) The same spectrum from Moscow group of HM. 1995-2001 data without problematic Det.3,5. 1)KGC has triggered a huge discussion 2) The best answer is the measurement! Check of KGC is now the target for all next generation  projects  ?

7. NEMO-3/SuperNEMO collaboration Neutrino Ettore Majorana Observatory (Neutrino Experiment on MOlybdenum – historical name) 80 physicists / 30 institutions

8. 3 m 4 m B (25 G) Source : 10 kg of  isotopes cylindrical, S = 20 m 2, 60 mg/cm 2 Tracking detector : drift wire chamber operating in Geiger mode (6180 cells) Gas: He + 4% ethyl alcohol + 1% Ar + 0.1% H 2 O Calorimeter : 1940 plastic scintillators coupled to low radioactivity PMTs The NEMO3 detector Fréjus Underground Laboratory : 4800 m.w.e. Magnetic field: 25 Gauss Gamma shield: Pure Iron (18 cm) Neutron shield: borated water (~30 cm) + Wood (Top/Bottom/Gaps between water tanks) Able to identify e , e ,  and  delayed 20 sectors

9. NEMO3 unique features Multi-source detector Measurement of full  -event pattern Self-determination of ALL background components measuring independent channels Multisource  -detector

10. Unique spectra from tracko-calo technique 100 Mo  2 Results NEMO-3 ’’  -factory’’ in action Sum energy spectrumAngular distributionSingle electron energy spectrum Data - MC ββ2 - background subtracted 100 Mo Latest results: 219 000 events 389 days S/B=40 100 Mo

11. 100 Mo  2 Results Summary of NEMO-3  -results Isotope Expo- sure, days EventsS/B T 1/2 (2νββ), years Published 100 Mo 38921900040 (7.11 ± 0.02(stat)±0.54(syst))·10 18 (SSD favored) 100 Mo(0 + 1 ) 334.337,54 (5.7 +1.3 -0.9 (stat) )±0.8(syst))·10 20 82 Se 38927504 (9.6± 0.3(stat)±1.0(syst))·10 19 116 Cd 168.413717.5 (2.8± 0.1(stat)±0.3(syst))·10 19 150 Nd 93920182.8 (9.11 +0.25 -0.22 (stat)±0.63(syst))·10 18 New preliminary 130 Te 11522360.35 (6.9± 0.9(stat)±1.0(syst))·10 20 96 Zr 12214281 (2.35± 0.14(stat)±0.16(syst))·10 19 48 Ca 943.21166.8 (4.4 +0.5 -0.4 (stat)±0.4(syst))·10 19 Systematic studies of  process provide crucial knowledge for  search!

12. 100 Mo  2 Results  -results Isotope T 1/2 (0νββ) limit, ×10 24 years, eVExperimentYear 76 Ge > 15.7<0.3-1.35IGEX2002 76 Ge 15.0.17-0.45HM(KGC)2004 76 Ge > 15.5<0.3-1.35HM(Others)2005 130 Te >3<0.2-0.7CUORICINO2008 100 Mo >1.1<0.45-0.93NEMO-32009

13. From NEMO to SuperNEMO SUPERNEMO R&D is in progress since 2006 NEMO-3  SuperNEMO 100 Mo, 7kg Isotope, mass 82 Se,100-200 kg 208 Tl: < 20  Bq/kg 214 Bi: < 300  Bq/kg Background in  -foil 208 Tl: < 2  Bq/kg 214 Bi: < 10  Bq/kg 8% Efficiency 30% 8% @ 3 MeV Energy resolution (FWHM) 4% @ 3 MeV T 1/2 > 2 x 10 24 y < 0.3 – 0.8 eV Sensitivity T 1/2 > 1-2 x 10 26 y < 40 – 100 meV NEMO-3 successful experience allows to extrapolate tracko-calo technique on larger mass next generation detector to reach new sensitivity level.

14. 20 modules, each of them hosts: - 5 kg of source foil ( 82 Se, 40mg/cm 2 ) - 2000-3000 Geiger channels - 600 Calorimeter channels: PVT Scintillator + 8’’ PMT SuperNEMO basic design SuperNEMO module SuperNEMO is the favorite project to be hosted in the new LSM laboratory (hall A) planned to be opened at 2013

15. SuperNEMO demonstrator SuperNEMO demonstrator (first module) being finalizing, which will: 1)Prove the concept 2)Test  at level of KGC 3)Start in 2012 Calorimeter R&D Tracker R&D Low background R&D Simulations Source: 6.3 kg of 82 Se BiPo setup

16. EXO-200 TPC CUORE Bolometer GERDA HPGe World leading  projects I

17. Experiment Iso- tope Mass *, kg T 1/2 10 25 y, 90% CL m, meV MethodStartStatus CUORICINO 130 Te110.24200-900bolometric2002 finished(2008) NEMO 3 100 Mo70.2300-810Tracko-calo2003 running GERDA, Ph-I 76 Ge153180-440HPGe (ion.)2010 construction Ph-II 76 Ge352070-170HPGe (ion.)2011 approved CUORE 130 Te2041340-92bolometric2012 construction EXO-200 136 Xe1606.4270-380Liquid TPC2010 construction SNO+ 150 Nd486.4<100 Liquid Scintillator 2011 construction SuperNEMO 82 Se100+10-2040-100Tracko-calo2012 Demonstrator MAJORANA 76 Ge28HPGe (ion.)2012 Demonstrator EXO 136 Xe80020050-68Gas TPC2015 R&D 0nbb experiments overview World leading double beta-decay projects II Others concepts and/or R&D: CANDLES ( 48 Ca), COBRA ( 116 Cd, 130 Te), DCBA ( 150 Nd), CARVEL ( 48 Ca), CAMEO ( 116 Cd), XMASS ( 136 Xe), GEM ( 76 Ge), GSO ( 76 Ge), NEXT ( 136 Xe), MOON ( 100 Mo) * Pure mass of  -isotope. Efficiencies are NOT included.

18. KGC NEMO 3 CUORICINO, EXO-200 GERDA SuperNEMO CUORE,EXO 2015-2020, 1t experiments (1 or 2) >2020, >10t experiment Roadmap for double beta-decay projects

19. - The 0  decay is a test of physics beyond the Standard Model, fundamental neutrino properties: nature, absolute mass scale and neutrino hierarchy. - NEMO-3 detector is very efficient “  -factory”, which is producing world leading results in the  -field. - SuperNEMO R&D program has confirmed that NEMO-3 technique can be successfully extrapolated to 100 kg experiment with sensitivity compatible with other world leading projects. -SuperNEMO team is finalizing the design of SuperNEMO Demonstrator (first module) which will prove the workability of technique and check KGC. The Demonstrator will be started in 2012. - Positive signal from 2-3 experiments with different sources and different techniques would be guaranteed confirmation of the existence of  -process. - Only tracko-calo and gas TPC can directly register  -decay. In the case of discovery only direct methods will allow to determine the process leading to  : light neutrino exchange, right-handed current, supersymmetry, etc. Conclusion