Search for Neutrinoless DoubleBeta Decay Werner Tornow Duke

Search for Neutrinoless Double-Beta Decay Werner Tornow Duke University & Triangle Universities Nuclear Laboratory (TUNL) & Kavli-Tokyo Institute of the Physics and Mathematics of the Universe On behalf of the Kam. LAND-Zen Collaboration

1. Introduction 2. Beta-and Double-Beta Decay 3. Kam. LAND-Zen 4. Look into the Future of 0 nbb Searches

Neutrino Mass T. O’Donnell

T. O’Donnell

Oscillation experiments provide the mass splittings Solar matter effects provide the sign of dm 221 T. O’Donnell Don’t know the sign of dm 223 Don’t know the absolute mass scale

Beta and Double-Beta Decay

Ordinary (2 nbb) Double-Beta Decay T. O’Donnell Observed for 100 Mo and 150 Nd also to 1 st excited 0+ state of daughter nucleus

Neutrinoless (0 nbb) Double-Beta Decay Lepton number violation Not allowed in SM T. O’Donnell

Rule of Thumb: Half-time sensitivity: N = Number of nuclei of the desired isotope t = Measuring time B = Number of background counts in the region of interest DE= Energy resolution in the region of interest

0 nbb Experiments Isotope Experiment 48 Ca Candles Gerda, Majorana Demonstrator Super. NEMO MOON Cobra CUORE, Cobra, SNO+ EXO, NEXT, Kam. LAND-Zen 76 Ge 82 Se 100 Mo 116 Cd 130 Te 136 Xe

Search for 0 nbb of 136 Xe with Kam. LAND-Zen

46 scientists form 11 institutions

LS: 82% Decane, 18% Pseudocumene, PPO 2. 7 g/l

0 nbb search was envisioned already in the original U. S. Kam. LAND proposal to DOE (1999) as the end phase of Kam. LAND Concrete plans were not developed before 2009 Reactor, geoneutrinos and supernova watch Kam. LAND-Zen only 1. 4% of Kam. LAND liquid scintillator volume

25 mm Nylon film 13 ton LS 2458 ke. V

Neutrino 2014 result

Half-Life Limits EXO: T 1/2 > 1. 1 x 1025 yr (90% CL) 136 Xe WIPP Kam. LAND-Zen: T 1/2 > 2. 6 x 1025 yr (90%CL) 136 Xe Kamioka Nature, 510, 229 (2014) preliminary GERDA: PRL, 111, 122 (2013) T 1/2 > 2. 1 x 1025 yr (90% CL) 76 Ge LNGS GERDA combined with HDM and IGEX: T 1/2> 3. 0 x 1025 yr H. V. Klapdor-Kleingrothaus et al. , Eur. Phys. J. A 12, 147 (2001) H. V. Klapdor-Kleinkrothaus et al. T 1/2=1. 19 x 1025 yr C. E. Aalseth et al. , Phys. Rev. D 65, 092007 (2002) Phys. Lett. B 586, 198 (2004)

Look into the Future Kam. LAND-Zen CUORE Super. NEMO NEXO, NEXT SNO+ 1 -tonne 76 Ge Experiment

Neutrino 2014

CUORE 988 750 g Te. O 2 bolometers 204 kg of 130 Te 2. 1 x 1026 yr @LNGS

Super. NEMO 82 Se: Electron Tracking, 1 x 1026 yr Frejus Underground Laboratory, France NEMO 3

NEXO Larger and improved version of EXO-200 Xenon-based Time-Projection – Chamber few 1026 yr SNOLAB ? Waste Isolation Pilot Plant (WIPP) in Carlsbad, NM, USA FV: 76. 3 kg of 136 Xe

SNO+ Tellurium loaded Liquid Scintillator few 1026 yr

MAJORANA DEMONSTRATOR @ SURF Enriched LAr GERDA: HPGe GERmanium Detectors Detector The two collaborations plan to join forces to build Array @LNGS a 1 -tonne 76 Ge based 0 nbb experiment using the better of the two approaches: a few 1026 yr

Within the next 5 to 10 years : Several experiments will push the T 1/2 (0 nbb) limit to > 1026 yr Effective neutrino mass range down to ~30 me. V will be probed (“center” of inverted hierachy region)