Double Beta Decay - status and future Double beta decay basics Double beta decay basics Experimental challenges Experimental challenges Current experimental status Current experimental status HM(HKK) result HM(HKK) result Future experimental programmes Future experimental programmes Dark matter and  Dark matter and  Based on talks at ApPEC Peer Review of , Nu2002 (heavily) ….and a night in the Lamb with Kai Züber and Roland

Double Beta Decay Cremonesi Nu2002

 Rates Cremonesi Nu2002

Why do  ? Cremonesi Nu2002

Experimental Considerations Cremonesi Nu2002 Measure this

Key Issues Multi-isotopic targetsMulti-isotopic targets –“Redundancy, redundancy, redundancy” (J. Bahcall) –Background removal by different peak positions (ie noise peak at Q) EnrichmentEnrichment Radio-isotopic backgroundsRadio-isotopic backgrounds Energy ResolutionEnergy Resolution DiscriminationDiscrimination –Removal of gamma, beta, neutron backgrounds –  background irremovable (separate peaks) –Co-location of daughter ion TheoryTheory –Matrix elements Analysis techniquesAnalysis techniques –Esp. in light of H-M claim

Current Experimental Limits Cremonesi Nu2002

Current Experimental Limits Cremonesi Nu2002

Heidelberg Moscow Experiment Cremonesi Nu2002

HM(HVKK) Result Cremonesi Nu2002

HM(HVKK) Result Cremonesi Nu2002

Comments on HM(HVKK) Cremonesi Nu2002

Reply to the comments on HM(HVKK) Cremonesi Nu2002

IGEX: Canfranc hep-ex

Thermal detectors - Milano DB Cremonesi Nu2002

Milano DBD-II Cremonesi Nu2002

MDBD-II: Results Cremonesi Nu2002

MDBD-II: Background Cremonesi Nu2002

Proposed Experiments Cremonesi Nu2002

Proposed Experiments Elliott and Vogel Ann. Rev. Nucl. Part. Sci. 52 (2002) 10’s kg scale Tonne scale Half life normalised to 5 years operationHalf life normalised to 5 years operation Matrix element range. Half life for 50meV mass (in y)Matrix element range. Half life for 50meV mass (in y)

Modularity and prototyping ModularityModularity –Discrimination through segmentation –Increase in support materials GENIUS vs. Majorana –Systematics checks PrototypingPrototyping –Direct scale-up of current technology won’t require prototyping - too expensive? –Prototype is first module –All experiments involved in prototyping Handling scale up issues (cryostats, mass, etc) Handling readout options (laser tag, WLS fibres) Cross check against Monte Carlo

NEMO-IIINEMO-III Cremonesi Nu2002

NEMO-IIINEMO-III

CUORECUORE

CUORicinoCUORicino

EXO - Xenon Cremonesi Nu2002

EXO - two approaches Cremonesi Nu2002

MajoranaMajorana

GENIUSGENIUS

GENIUS-TFGENIUS-TF

GEMGEM

DCBA/COBRADCBA/COBRA

Pros and Cons TechniquePrototypingMultiIsotopeEnrichmentResolution Mass limit DiscriminationProblems CAMEO CdWO 4 scintillator Use of B-CF 65kg array NoNeeded10% 1 tonne Active shield Enrichment costs COBRACdTediodesUnderwayYes No (?) <1%10kgSegmemtation Neutron background CUORE TeO 2 Bolometer Cuoricino approved No Not needed (34% natural) 0.2% 1 tonne Active shield Segmentation Materials close to target EXO LXe or Xe TPC Approved (Ba tag test, 100kg Lxe) NoNeeded<2% 10 tonne Co-location of daughter PSD Cost of enrichment Ba ion extraction GENIUS Naked HPGe Genius-TF approved No G-TF: natural G: 86% enrichment 0.3% 1 tonne PSD Cost of enrichment Use of LN Cosmogenics MajoranaHPGe 1 Ge det under construction No Needed (8% -> 86%) 0.3%420kgSegmentationPSD Cost of enrichment MOON Mo & Scintillator WLS/Scint/Mo testing NoYes7% 3 tonne (34 tonnes nat. Mo) Localisation High Q (3.03MeV) Resolution NEMO Tracking chamber Scintillator NEMO-I/IIYesYes10%10kgTracking Time of flight Magnetic field Radioisotopic impurity Scale-up? TGVHPGe CaCO 3 foils TGV 1 (1g) No Required (73%) 0.2% ? TGV-2: 10g Enrichment from CaF 2 Mass

Many common elements for rare event searchesMany common elements for rare event searches –Theoretically prejudice for max sensitivity required DM: pb covers most of SUSY models  : >10 meV from oscillations Both require large mass targets (~1 tonne) –Low backgrounds required High radio-purity materials Good shielding –Discrimination required DM: nuclear vs. electron recoil, spatial  : spatial (co-location of daughter) –Good resolution/threshold (high light yield, etc.) DM: keV range - bite into DM spectrum  : MeV range - separate peaks at Q Can we do both in one detector?Can we do both in one detector? –Xenon is an obvious candidate to consider within U.K.  and dark matter Beware!

Xenon experience in UK/RAL Gotthard Xe TPC DB experiment (Roland) ZEPLIN dark matter programme (RAL, IC, Shef)

ZEPLIN as  experiment Developing ideas for combining dark matter and  experimentsDeveloping ideas for combining dark matter and  experiments Key issues are –Energy scales of interest Primarily a DAQ issue, saturation of readouts, etc. –Discrimination of backgrounds Can position sensitivity in ZEPLIN be improved to check co-locality in DB? –Resolution at MeV scales Looks OK in second generation DM targets There is also     capabilityThere is also     capability – 124 Xe (0.1% in nat. Xe) is one of seven known     emitters –     gives 4x 511keV photon signal –   EC  gives X-ray (30keV) and 2x 511keV photon signal ( –  ECEC  gives 2x X-ray (30keV) signal Current limits for 124 Xe are T > 2x10 14 years, T > 4x10 17 years

ConclusionsConclusions The bb0n decay search has the promise of illuminatingThe bb0n decay search has the promise of illuminating –Absolute mass scale of neutrinos (note this is effective mass, unlike beta end point: KATRIN) –Lepton number violation –Majorana vs. Dirac description Current limits/claims 300meVCurrent limits/claims 300meV –H-M (HVKK) Claim contested Oscillation results encourage meV searchesOscillation results encourage meV searches Several programmes suggested on Ge, Xe, Te, MoSeveral programmes suggested on Ge, Xe, Te, Mo –Need large scale, good resolution, discrimination, enrichment Possibility of DM detectors as DBPossibility of DM detectors as DB –ZEPLIN programme? –One man’s background….