Neutrinoless double-beta decay and the SuperNEMO project. - HEP
Neutrinoless double-beta decay and the SuperNEMO project. - HEP
Neutrinoless double-beta decay and the SuperNEMO project. - HEP
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SuperNemoStefan Söldner-Rembold/Darren PriceUniversity of ManchesterChristmas Meeting4 Januar 200524 November, 2004
NEMO3:●●●●NEMO = Neutrino Ettore Majorana ObservatorySearch for neutrinoless <strong>double</strong>-<strong>beta</strong> <strong>decay</strong> (0)Operates at <strong>the</strong> Fréjus Underground Laboratory in Savoie,France– NEMO Collaboration exists since 1989●NEMO-2● NEMO-3 started data taking in 2003Planned to be running until 2007-8 when hopefully(!)superseded by SuperNemo
<strong>Neutrinoless</strong> <strong>double</strong><strong>beta</strong> <strong>decay</strong>●●●Double <strong>beta</strong> <strong>decay</strong> - nucleus simultaneouslyreleases two electrons with ei<strong>the</strong>r with two or noneutrinos in <strong>the</strong> final stateIn 2νββ, two neutrinos observed, satisfies leptonnumber conservationIn 0νββ, no neutrinos – lepton number violationAZA X Z2Y 2e ?veMajorana neutrinos:particle <strong>and</strong> anti-particle identicalDirac neutrinos:particle <strong>and</strong> anti-particle distinctonly relevant if m ν>0 (oscillations !)
Half life of 0νββ17a v~ 5F010yT1 20vphase space factor0 vM0v 1nuclear matrix elementmmvea0vFdimensional factor0 vM0vlog 225 Q 2Electron energy estimate of neutrinomass scale
NEMO3:●●Experimentally <strong>the</strong> <strong>double</strong><strong>beta</strong> <strong>decay</strong>s onlydistinguished by <strong>the</strong>irdifferent electron energyspectraConstructed to detectemitted electrons fromisotopes known toproduce <strong>double</strong> <strong>beta</strong><strong>decay</strong>, whilst reducingany background effects.
NEMO3 contains 10kg of isotopes primarily enrichedMolybdenum (6.9kg) sensitivity:(0.15-0.5) eVTT2 821/ 22 1001/ 2( Se)( Mo)~ 10factor of 10 lower BG for 82 SeIsotopes produced in Russia
NEMO events28/01/04 Ruben Saakyan, UCL IOPmeeting, Sussex7
From NEMOIII to <strong>SuperNEMO</strong>●Very well known <strong>and</strong> working technology●Successful detector operation <strong>and</strong> physics results withNEMO-II <strong>and</strong> NEMO-III●Improvements (zero BG experiment !)●●- better energy resolution (∆E/E~10%)- bigger volume (x10)Modest amount of isotope needed (100kg of 82 Se)– Current enrichment capabilities – 30 kg/yr maxShort time scale <strong>and</strong> modest price– 40-50 meV by 2014– ~15 M GBP
Nemo-3Ray Thompson<strong>and</strong> SSR visitedOrsay to seeconstructionfacilities
Sur un pétale
NEMO2 vue généraleSupernemo will be similarto Nemo-2 (planar geometry),not Nemo-3 (cylindrical geometry)1 m 2
NEMO2 changement de source
SuperNemo: Time Scale●●●●●●2004-2005: scintillator R&D2006-2007: Development <strong>and</strong>characterization of 1 st submodule2007-2008: Start <strong>SuperNEMO</strong>installation2009-2010: Start taking data2014: planned sensitivity ~0.04 eVExcellent chance to be <strong>the</strong> first toreach 40-50 meV
SuperNemo Location ?Boulby ?Frejus
Activities in Manchester2004:- GEANT-3 simulation of SuperNemo (Darren)- Visits at Orsay <strong>and</strong> UCL2005:- 11-13 January: Meeting of UK/French groups at Manchesterto prepare proposals- March: ask PPRP for funding for <strong>the</strong> next 2 years- April: start work on tracking detectorstart building first module in 2006
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