IOP HEPP Matthew Kauer Double beta decay of Zr96 using NEMO- 3 and calorimeter R&D for SuperNEMO IOP HEPP April Matthew Kauer UCL London

IOP HEPP Matthew Kauer Theory and motivation Phase space Nuclear matrix element v e effective mass Half-life 2vbb allowed in Standard Model (SM) input to 2vbb nuclear matrix element (NME) calculations useful for 0vbb NME calculations key background to 0vbb (irreducible) 0vbb beyond SM: x2 total lepton number violation most sensitive way to establish Majorana/Dirac nature of neutrino most sensitive way to measure absolute v mass in a lab environment (for Majorana v’s) possible access to v mass hierarchy and Majorana CP- violation phases link to matter-antimatter asymmetry (leptogenesis) Insert new physics here

IOP HEPP Matthew Kauer NEMO-3 Detector tracker (6k drift cells) calorimeter (2k PM’s) magnetic field (25 Gauss) 10 kg of source (7 isotopes) passive shielding (4.8k MWE) 0.3 eV sensitivity (2 x yr)

IOP HEPP Matthew Kauer Backgrounds 1 electron, Zr96 foil electron + gamma, Zr96 foil Verify external bkg with Cu My analysis on Zr g isotope electron + gamma, Cu foil

IOP HEPP Matthew Kauer 2vbb Measurement 2vbb signal (blue) is scaled until the log-likelihood is maximized Previous Measurement from NEMO-2 T 2v = [ (stat) +/- 0.2(syst)] x yr 911 days runtime

IOP HEPP Matthew Kauer 0vbb Discussion Limits on various 0v modes (half-lives in years):

IOP HEPP Matthew Kauer Isotope Isotope Mass M Efficiency  Internal Bkgs Energy Resolution Sensitivity 82 Se (and/or 150 Nd if enrichment possible) kg ~ 30 %  10  Bq/kg 4% 3 MeV  ( 1 MeV )    ) > y  m   < eV SuperNEMO R&D on: Isotope enrichment Drift cell tracker Software Calorimeter UCL London CENBG Bordeaux, LAL Orsay INR Kiev, ISMA Kharkov JINR Dubna Univ. Texas Austin 1 of 20 sub-modules each with ~5-7 kg of isotope

IOP HEPP Matthew Kauer Test Bench 207 Bi CE source Hamamatsu (35% QE) PMT BC404 scintillator wrapped in Teflon  E/E = 6.5% 1 MeV 2mm Al. filters out CE’s fit the gamma spectra carry parameters over  976 keV ce-K 1048 keV ce-L 482 keV ce-K 554 keV ce-L

IOP HEPP Matthew Kauer Baseline Design 18cm 8” Hamamatsu R5912-MOD Super-Bialkali 8 Dynodes 25cm Eljen EJ200 PolyVinylToluene ~10k ph/MeV Glycerol or 2-propanol optical coupling % 1 MeV < 1% deviation Reflective wrappings: 75um Teflon ≥85% diffusive 100um ESR ~95% specular

IOP HEPP Matthew Kauer Results Scint 1 MeV PMT Size and Make 5 2 x 2 cm BC %3in Ham-SBA 9 2 x 2 cm BC %8in Ham-SBA w/ LG 14 2 x 2 cm BC %8in ETL w/ LG 15 2 x 2 cm BC %8in Ham-SBA w/ LG 20 (hex) x 2 cm BC %8in Ham-SBA w/ LG 20 (hex) x 2 cm EJ %8in Photonis XP (hex) x 10 cm EJ %8in Ham-SBA R5912-MOD 20 (hex) x 10 cm EJ %8in Photonis XP1886 Independent verification with calibrated Sr90 test-bench at CENBG, Bordeaux. error ± 0.5%

IOP HEPP Matthew Kauer Conclusions ΔE/E = 7.1% FWHM at 1 MeV 32% QE PM 10k ph/MeV PVT World best Zr96 Measurement: Unprecedented ΔE/E for low Z scint: Full write-up about to be submitted to NucPhys A To be submitted to NIM A

IOP HEPP Matthew Kauer BONUS

IOP HEPP Matthew Kauer Event Reconstruction Sophisticated event reconstruction: single electron electron + gamma(s) electron + delayed alpha gamma(s) + alpha etc… Separation of source and detector Calorimeter Drift cell tracker in Geiger mode Time-of-flight information Magnetic field for charge identification

IOP HEPP Matthew Kauer External Backgrounds arXiv: v1 [nucl-ex], submitted to NIM A

IOP HEPP Matthew Kauer Internal Backgrounds 1 electron, 911 days runtime

IOP HEPP Matthew Kauer Internal Backgrounds 1 electron + 1 gamma, 911 days runtime

IOP HEPP Matthew Kauer 2vbb Measurement maximized log- likelihood fit

IOP HEPP Matthew Kauer 0vbb Discussion Limits obtained via the log-likelihood ratio test statistic:

IOP HEPP Matthew Kauer Majorons

IOP HEPP Matthew Kauer SuperNEMO SuperNEMO ~ 90 physicists, 12 countries currently on 3 year R&D phase (ends late ’09) Isotope Isotope Mass M Efficiency  Internal Bkgs Energy Resolution Sensitivity 82 Se (and/or 150 Nd if enrichment possible) kg ~ 30 %  10  Bq/kg 4% 3 MeV  ( 1 MeV )    ) > y  m   < eV R&D on: Isotope enrichment Drift cell tracker Software Calorimeter UCL London CENBG Bordeaux, LAL Orsay INR Kiev, ISMA Kharkov JINR Dubna Univ. Texas Austin

IOP HEPP Matthew Kauer M mass (g)  efficiency k C.L. confidence level N Avogadro number t time (y) N Bkg background events (keV -1.g -1.y -1 )  E energy resolution (keV) > AA M. t N Bkg.  E (y). ln2 N k C.L.. 12% 1 MeV 8% 1 MeV Even with ideal M, N bkg,   2 and 0 mix at low  E Energy Resolution

IOP HEPP Matthew Kauer The Detector Single sub-module with ~5-7 kg of isotope ~20 sub-modules for 100+ kg of isotope surrounded by water shielding ~ 40-60k Geiger channels for tracking ~ 10-20k PMTs source foils water