nemo-3 bb experiment first results and future prospects
DESCRIPTION
NEMO-3 bb experiment First Results and Future Prospects. Ruben Saakyan, UCL UK HEP Neutrino Forum The Cosener’s House, Abingdon. Outline. Why NEMO-3 ? The Detector First results Sensitivity by 2007 Towards SuperNEMO. Currently Active Experiments. CUORICINO (bolometer). NEMO-3 - PowerPoint PPT PresentationTRANSCRIPT
NEMO-3 experimentFirst Results and Future
Prospects
Ruben Saakyan, UCLUK HEP Neutrino Forum
The Cosener’s House, Abingdon
Outline
Why NEMO-3 ? The Detector First results Sensitivity by 2007 Towards SuperNEMO
Currently Active Experiments
<m> = 0.4 eV ???
CUORICINO (bolometer)
NEMO-3(Tracking calorimeter)
Heidelberg-Moscow exp is still running
Why NEMO-3 ? One of the two experiments to improve
<m> 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
Neutrino Ettore Majorana Observatory
40 physicists and engineers
13 Laboratories/Universities
7 Countries
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)
• 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- 207Bi, 90Sr for energy calibration• 60Co for time alignment
Trigger:1 scintillator hit > 150 keV +1 track: few Geiger planes(flexible 3 – 7 Hz)
NEMO events
3D pictures study single electron spectra study angular distributions
Detailed 2information O (105) 2 100Mo events/yr ! 7 isotopes
NEMO background events
e+e- e- (~7 MeV) from n
Pure materials:
Source foils measured with the NEMO-3 detector
• 208Tl < 2 Bq/kg• 214Bi < 2Bq/kg • neutrons < 10-9 n cm-2s-1
Radon in the detector• 222Rn ~ 20 mBq/m3
• 220Rn ~ 1.6 mBq/m3
to be improved with new anti-radon system
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
NEMO-3 First Results100Mo 1200 h
2:T1/2=[7.4±0.05(stat)±0.8(sys)]×1018yr (19000 events; S/B 50)
0:1 event in 2.8 – 3.2 MeV regionT1/2 > 1023 yr 90% CL<m> < 0.9 – 2.1 eV
World’s best result for 100Mo
Single State Dominance (SSD)VS
Higher order State Dominance (HSD)
Simkovic, Domin, Semenovnucl-th/0006084, Phys. Rev. C
100Mo
100Tc
100Ru
0+
1+
0+
SSD
HSD
1. Shape of single e- spectrum2. Shape of 2 spectrum3. Angular distribution4. ~ 20% difference in T1/2
100Mo + NEMO-like detector can test it experimentally !
NEMO-3 First Results100Mo 1200 h
single e- spectrum Angular distribution between two e-
Preliminary: SSD is preferred
NEMO-3 First ResultsOther Isotopes
T1/2=[8.2±0.4(stat)±0.8(sys)]×1019
T1/2 > 4 × 1022 y 90% CLWorld’s best result !
T1/2=[7.0±0.7(stat)±0.7(sys)]×1018
T1/2 > 7.7 × 1020 y 90% CL
T1/2=[3.9±0.3(stat)±0.4(sys)]×1019
T1/2 > 1.0 × 1022 y 90% CL
82Se 150Nd 116Cd
NEMO-3 0 sensitivity5 years
100Mo7 kg Q =3.034 MeV
External BG: 0 Internal BG:
radioactivity < 0.04 event/y/kg = 0.11 event/y/kg
T1/2 > 3 × 1024 yr
<m> < 0.2 – 0.5 eV
E = 2.8 – 3.2 MeV 82Se
1 kg Q =2.995 MeVExternal BG: 0
Internal BG: radioactivity < 0.01 event/y/kg
= 0.01 event/y/kg
T1/2 > 1 × 1024 yr
<m> < 0.6 – 1.2 eV
In case of full load of 82Se (~14kg) <m> < 0.15 – 0.3 eV
SuperNEMO (not an official proposal yet)
Sensitivity <m> ~ 0.05 eV in 5 yr
~ 100 kg 82Se (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)
Future projects comparison
Experiment Source and Mass
Sensitivity toT1/2 (y)
Sensitivity to<m> (eV)*
Majorana$50M
76Ge, 500kg
3×1027 0.03 – 0.07
CUORE$25M
130Te, 750kg(nat)
2×1026 0.05 – 0.17
EXO$50M-100M
136Xe1 ton
8×1026 0.05 – 0.12
SuperNEMO$15M
82Se(or other)
100 kg2×1026 0.05 – 0.11
* 5 different latest NME calculations
Concluding Remarks 1200 h, T1/2(2) for 4 isotopes; World’s best
results for T1/2(0) for 100Mo, 82Se By 2007/2008
NEMO-3 to reach <m> < 0.15 - 0.5 eV (depending on 82Se 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
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
BACKUP SLIDES
T01/2 = G0 |M0|2 <m>2
T21/2 = G2 |M2|2