1. NEMO-3  experiment First Results and Future Prospects Ruben Saakyan, UCL UK HEP Neutrino Forum The Cosener’s House, Abingdon

2. Outline Why NEMO-3 ? The Detector First results Sensitivity by 2007 Towards SuperNEMO

3. Currently Active Experiments = 0.4 eV ??? CUORICINO (bolometer) NEMO-3 (Tracking calorimeter) Heidelberg-Moscow exp is still running

4. Why NEMO-3 ? One of the two experiments to improve sensitivity before 2007/2008 (0.15  0.5 eV) for a few isotopes Well known (for us) technique orthogonal to other approaches Excellent chance to understand nitty gritty of  experiment…..and choose a project to attack n×10 -2 eV scale

5. Neutrino Ettore Majorana Observatory 40 physicists and engineers  13 Laboratories/Universities  7 Countries

6. UK NEMO team (so far) Phil Adamson, Leo Jenner, Ruben Saakyan, Jenny Thomas (all UCL) Received approval from PPRP 27 Jan 03 Main involvement: data analysis....but also some hardware tasks (PMT helium tests, light injection optimization)

7. From scintil detector:   = 250 ps From tracker:  || = 1cm   = 0.45mm (using timing information on plasma propagation) Calibration: Laser survey neutron Am/Be for  ||,  , e + signature e - 207 Bi, 90 Sr for energy calibration  60 Co for time alignment Trigger: 1 scintillator hit > 150 keV + 1 track: few Geiger planes (flexible  3 – 7 Hz)

8. NEMO  events  3D pictures  study single electron spectra  study angular distributions  Detailed 2  information  O (10 5 ) 2 100 Mo events/yr !  7 isotopes

9. NEMO background events  e + e - e - (~7 MeV) from n 

11. Pure materials: Source foils measured with the NEMO-3 detector 208 Tl < 2  Bq/kg 214 Bi < 2  Bq/kg neutrons < 10 -9 n cm -2 s -1 Radon in the detector 222 Rn ~ 20 mBq/m 3 220 Rn ~ 1.6 mBq/m 3 to be improved with new anti-radon system

14. Data taking June 2002: start with all 20 sectors, iron shielding, neutron shielding but… …still a lot of debugging (both tracking detector and calorimeter) 14 February 2003: start of routine data taking

15. NEMO-3 First Results 100 Mo 1200 h 2 : T 1/2 =[7.4±0.05(stat)±0.8(sys)]×10 18 yr (19000 events; S/B  50) 0 : 1 event in 2.8 – 3.2 MeV region T 1/2 > 10 23 yr 90% CL < 0.9 – 2.1 eV World’s best result for 100 Mo

16. Single State Dominance (SSD) VS Higher order State Dominance (HSD) Simkovic, Domin, Semenov nucl-th/0006084, Phys. Rev. C 100 Mo 100 Tc 100 Ru 0+0+ 1+1+ 0+0+ SSD HSD 1.Shape of single e - spectrum 2.Shape of 2  spectrum 3.Angular distribution 4.~ 20% difference in T 1/2 100 Mo + NEMO-like detector can test it experimentally !

17. NEMO-3 First Results 100 Mo 1200 h single e - spectrum Angular distribution between two e - Preliminary: SSD is preferred

18. NEMO-3 First Results Other Isotopes T 1/2 =[8.2±0.4(stat)±0.8(sys)]×10 19 T 1/2 > 4 × 10 22 y 90% CL World’s best result ! T 1/2 =[7.0±0.7(stat)±0.7(sys)]×10 18 T 1/2 > 7.7 × 10 20 y 90% CL T 1/2 =[3.9±0.3(stat)±0.4(sys)]×10 19 T 1/2 > 1.0 × 10 22 y 90% CL 82 Se 150 Nd 116 Cd

19. NEMO-3 0  sensitivity 5 years 100 Mo 7 kg Q  =3.034 MeV External BG: 0 Internal BG: radioactivity < 0.04 event/y/kg  = 0.11 event/y/kg  T 1/2 > 3 × 10 24 yr  < 0.2 – 0.5 eV E = 2.8 – 3.2 MeV 82 Se 1 kg Q  =2.995 MeV External BG: 0 Internal BG: radioactivity < 0.01 event/y/kg  = 0.01 event/y/kg  T 1/2 > 1 × 10 24 yr  < 0.6 – 1.2 eV In case of full load of 82 Se (~14kg) < 0.15 – 0.3 eV

20. SuperNEMO (not an official proposal yet)  Sensitivity ~ 0.05 eV in 5 yr ~ 100 kg 82 Se (or other) 4 supermodules, planar geometry Feasible if: a)BG only from 2 (NEMO3) b)  E/E = 10-11% at 1 MeV (R&D needed)

21. Future  projects comparison ExperimentSource and Mass Sensitivity to T 1/2 (y) Sensitivity to (eV) * Majorana $50M 76 Ge, 500kg3×10 27 0.03 – 0.07 CUORE $25M 130 Te, 750kg(nat) 2×10 26 0.05 – 0.17 EXO $50M-100M 136 Xe 1 ton 8×10 26 0.05 – 0.12 SuperNEMO $15M 82 Se (or other) 100 kg 2×10 26 0.05 – 0.11 * 5 different latest NME calculations

22. Concluding Remarks 1200 h, T 1/2 (2 ) for 4 isotopes; World’s best results for T 1/2 (0 ) for 100 Mo, 82 Se By 2007/2008 NEMO-3 to reach < 0.15 - 0.5 eV (depending on 82 Se availability) Several isotopes will be investigated Unprecedented high 2 statistics with detailed information (single e - spectra, angular distributions) for 7 isotopes  Experimental input to NME calculation

23. Concluding Remarks II NEMO-3 will test experimentally feasibility of SuperNEMO If yes  0.05 eV is achievable at relatively low cost and with very well known technology If not  will not waste time and money and do something else

24. BACKUP SLIDES

29. T 0 1/2 = G 0 |M 0 | 2 2 T 2 1/2 = G 2 |M 2 | 2