1. Search for Neutrinoless Double Beta Decay with NEMO-3 Zornitza Daraktchieva University College London On behalf of the NEMO3 collaboration PANIC08, Eilat, 10 November, 2008

2. Neutrinoless double beta decay (0  ) and double beta decay(2  ) experimental signatures 0  is the most sensitive tool to establish the nature of neutrinos (Dirac or Majorana). 0  can measure the absolute (Majorana) neutrino mass. 2  is an input into 0  NME calculation Ultimate background of 0  decay Two electrons in the final state The sum of energy of two electrons is Q  =E 1 +E 2   100 Mo Energy (MeV) 1 23 Zornitza Daraktchieva for the NEMO3 collaboration, PANIC08, Eilat, 10 November, 2008

3. NEMO3 experiment (Neutrino Ettore Majorana Observatory 60 physicists, 17 institutions The experiment is hosted in the Fréjus Underground Laboratory(4800 m.w.e) situated on the French Italian boarder. Zornitza Daraktchieva for the NEMO3 collaboration, PANIC08, Eilat, 10 November, 2008

4. Source : 10 kg of  isotopes ( 20 m 2, 50 μm) 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) The NEMO-3 detector Calorimeter: 1940 plastic scintillators coupled to 3” and 5” PMT Energy resolution : FWHM=14% and 17% @ 1 MeV The detector has been taking data since 2003 Tracker: 6180 drift wire chambers operating in Geiger mode Gas: He + 4% ethyl alcohol + 1% Ar + 0.1% H2O 4m Magnetic field: 25 Gauss 3m Unique traco-calo technique Zornitza Daraktchieva for the NEMO3 collaboration, PANIC08, Eilat, 10 November, 2008

5.  isotope foil scintillators PMTs Calibration tube Cathode rings Wire chamber A look inside the detector Zornitza Daraktchieva for the NEMO3 collaboration, PANIC08, Eilat, 10 November, 2008

6. 100 Mo 6.914 kg Q  = 3034 keV 82 Se 0.932 kg Q  = 2995 keV 116 Cd 405 g Q  = 2805 keV 96 Zr 9.4 g Q  = 3350 keV 150 Nd 37.0 g Q  = 3367 keV Cu 621 g 48 Ca 7.0 g Q  = 4272 keV nat Te 491 g 130 Te 454 g Q  = 2529 keV  measurement External bkg measurements  search  isotopes in NEMO 3 detector Zornitza Daraktchieva for the NEMO3 collaboration, PANIC08, Eilat, 10 November, 2008

7. Typical background events crossing electron electron-alpha from Bi-Po decay (164  s) electron positron pair electron + several gammas Zornitza Daraktchieva for the NEMO3 collaboration, PANIC08, Eilat, 10 November, 2008

8. Typical  candidate event Two electrons (long tracks with negative curvature Q<0) Two PMT scintillator counters hits associated with tracks (E >200 keV) Common vertex Internal event from the foil (time of flight cut) No PMT scintillator counters hits without tracks (rejection of the  background) No delayed short tracks (rejection of  background from Bi-Po decay mode) Selection criteria Zornitza Daraktchieva for the NEMO3 collaboration, PANIC08, Eilat, 10 November, 2008

9.  results with 100 Mo and 82 Se 100 Mo Background subtracted Data - Bgr 2  Monte Carlo 6914 g 389 days 219000 events S/B = 40 932 g 389 days 2750 events S/B = 4 82 Se Data - Bgr 2 Monte Carlo Background subtracted Phys. Rev. Lett. 95 182302 (2005) 100 Mo 2  decay T 1/2 = 7.11 ± 0.02 (stat) ± 0.54 (syst)  10 18 y 82 Se 2  decay T 1/2 = 9.6 ± 0.3 (stat) ± 1.0 (syst)  10 19 y Zornitza Daraktchieva for the NEMO3 collaboration, PANIC08, Eilat, 10 November, 2008

10. 2 results with 116 Cd and 130 Te Data-Bgr 454 g 534 days 109 events S/B = 0.25 130 Te Preliminary result: 116 Cd 2  decay T 1/2 = [2.8 ± 0.1 (stat) ± 0.3 (syst)]  10 18 y Preliminary result: 130 Te 2  decay T 1/2 = [7.6 ± 1.5 (stat) ± 0.8 (syst)]  10 20 y Zornitza Daraktchieva for the NEMO3 collaboration, PANIC08, Eilat, 10 November, 2008

11. Recent results : 48 Ca 48 Ca NME: E.Caurrier et al., Phys.Rev.Lett. 100(2008)052503 After chemistry 48 Ca is enough pure in 214 Bi, 208 Tl but 30mBq of 90 Sr! To suppress Møller scattering events from pure beta emitter ( 90 Y) cut out E 1 +E 2 0 133 events S/B 6.76 948 days 7g Preliminary results: T 1/2 (2  ) = [ 4.4 ± 0.50.4 (stat) ± 0.4 (syst) ]  10 19 y T 1/2 (0  ) > 1.3  10 22 y @ 90% C.L. [MCLIMIT] < 29.6 eV [NME] Zornitza Daraktchieva for the NEMO3 collaboration, PANIC08, Eilat, 10 November, 2008

12. Recent results: 96 Zr 9.4 g 925 days S/B = 1 [1] M.Kortelainen and J.Suhonen, Phys.Rev. C 75 (2007) 051303(R). [2] M.Kortelainen and J.Suhonen, Phys.Rev. C 76 (2007) 024315. [3] F.Simkovic et al., Phys.Rev. C 77 (2008) 045503. NME: Preliminary results: T 1/2 (2  ) = [2.3 ± 0.2(stat) ± 0.3(syst) ]  10 19 y T 1/2 (0  ) > 8.6  10 21 y @ 90% C.L. [MCLIMIT] < (7.4 – 20.1) eV [1-3] Zornitza Daraktchieva for the NEMO3 collaboration, PANIC08, Eilat, 10 November, 2008

13. New result: 2  150 Nd PRELIMINARY 939 days 37g T 1/2 (2νββ) = (9.11 +0.25 -0.22 (stat) ± 0.63 (syst)). 10 18 y (arXiv:0810.0248 ) 36.55 g Zornitza Daraktchieva for the NEMO3 collaboration, PANIC08, Eilat, 10 November, 2008

14. New result: 0  150 Nd PRELIMINARY 939 days 37g NME: [1] V.A.Rodin et al., Nucl.Phys. A 776 (2006) 107; A 793 (2007) 213 [2] J. H. Hirsh et al. Nucl;Phys.A 582(1995)124. T 1/2 (0  )>1.8 x 10 22 year @ 90% CL, (arXiv:0810.0248)  m  < 1.7 – 2.4 eV 1 not considering deformation  m  < 5.1 – 7.6 eV 2 considering deformation Zornitza Daraktchieva for the NEMO3 collaboration, PANIC08, Eilat, 10 November, 2008

15. 693 days of data Phase I + Phase II 693 days of data Phase I + Phase II 0  of 100 Mo and 82 Se 100 Mo 82 Se T 1/2 > 2.1 × 10 23 y @ 90% C.L.  m  < (1.4 – 2.2) eV [1-3] [1] M.Kortelainen and J.Suhonen, Phys.Rev. C 75 (2007) 051303(R). [2] M.Kortelainen and J.Suhonen, Phys.Rev. C 76 (2007) 024315. [3] V.A.Rodin et al., Nucl.Phys. A 793 (2007) 213. NME: T 1/2 > 5.8 × 10 23 y @ 90% C.L.  m  < (0.8 – 1.3) eV [1-3] Zornitza Daraktchieva for the NEMO3 collaboration, PANIC08, Eilat, 10 November, 2008

16. Summary NEMO 3 has been measured precise half-life time of seven  isotopes: 100 Mo, 82 Se, 116 Cd, 130 Te, 48 Ca, 96 Zr, and 150 Nd New 2  result for 150 Nd New 0  result for 150 Nd NEMO3 will be taking data till 2010 Future plans – Super NEMO project Please come and see Super NEMO poster to learn about our future plans! T 1/2  (9.11 +0.25 -0.22 (stat) ± 0.63 (syst)). 10 18 y T 1/2 (  1.8 x 10 22 year @ 90% CL Zornitza Daraktchieva for the NEMO3 collaboration, PANIC08, Eilat, 10 November, 2008