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

50 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)

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 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

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$20M

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