Status of AMoRE AMoRE (Advanced Mo-based Rare process Experiment) Presented by HongJoo Kim (KyungPook National Univ.) Seminar on Dark Matter and Double Beta Decay Search Sept. 22, 2011, YangYang , Korea

Neutrino No charge 3 flavor Mass /Mixing neutrino oscillation absolute mass? Type Dirac or Majorana? CP violation? Magnetic moment?

Double Beta Decay (2) n p e- e n p e- e (A,Z)  (A,Z+2) + 2 e- + 2e Here is beta decay, and here is double beta decay – both in the same nucleus. It only happens for certain nuclei that can’t undergo single beta decay. In these figures the energy released with a change in atomic number of 1 unit is shown on the left for nuclei with odd atomic mass number A, and for those with even atomic mass number. If the mass number is odd its always favourable to decay via a single beta decay – the isotopes tend towards the bottom of this energy parabola into a stable state. But for even A nuclei, there are two parabolas and sometimes the decay by a single beta requires energy input – so this step doesn’t happen, unless another energetically favourable beta decay happens simultaneously in the same nucleus. Thats simplified here – the intermediate step – a unitary chage in Z is energetically forbidden, but the combined process of two steps – a change in Z of 2 can occur. It turns out that there are only 35 isotopes known to undergo this process. This 2 neutrino double beta decay is a second order process in the standard model, but it does occur and has been observed. 0+ 1+ (A,Z) (A,Z+1) (A,Z+2) Only 35 isotopes known in nature

Double beta decay process 2n bb decay 2nd order beta decay Rare nuclear decay (>1018 years) 0n bb decay n mass>0 & Majorana particle 2) New Physics e ν N N’ 2νββ e ν N N’ 0νββ A B Transition bb allowed Forbidden  transition Z Energy Z+1 Z+2 Qbb 100Mo 100Ru 100Tc

History 1934: E. Fermi theory of weak interaction 1935: M. Goeppert Meyer discussed 2 1938: E. Majorana two component neutrino 1939: H. Furry discussed 0 1949: First half-life limits (Fireman, Fremlin,...) I thought it would be nice to take a look at the history of double beta decay. It was first proposed by Maria Goeppet-Mayer in 1935, and the zero mode was first discussed in 1939. It took a while for the first limits on the 2 neutrino mode half life. The first indirect evidence came from geochemistry and the first direct observation was reported in 1987 in an experiment situated under the Hoover dam. And in 2001 the first evidence for the neutrinoless mode was published but this has been widely disputed in the community. 1967: First geochemical evidence for 2 1987: First laboratory evidence for 2 2001: First laboratory evidence for 0???

First experimental results PHYSICAL REVIEW 146 (1966) 810 48CaF2(Eu), 19 g  T1/20 >21020 yr

Heidelberg -Moscow Many critism around!! T1/2 = 0.6 - 8.4 x 1025 yr Subgroup of collaboration T1/2 = 0.6 - 8.4 x 1025 yr m = 0.17 - 0.63 eV H.V. Klapdor-Kleingrothaus et al, Phys. Lett. B 586, 198 (2004)

Theory issues 1/T0n 1/2 = G0n(E0,Z) |M0n|2 <mbb>2, The decay rate is related to <mbb> by 1/T0n 1/2 = G0n(E0,Z) |M0n|2 <mbb>2, Where G0n(E0,Z) is calculable phase space factor (~ Qbb5), M0n-Nuclear Matrix Element, hard to calculate Uncertain to factor 2-10, isotope dependent Motivation to measure several isotopes The two basic and complementary methods of evaluating M are the nuclear shell model (SM) and the Quasiparticle Random Phase Approximation (QRPA) and its various modifications.

Nuclear Matrix Elements Prediction M. Lindner QRPA, RQRPA: V.Rodin, A. Faessler, F. Simkovic, P. Vogel, Nucl. Phys. A 793, 213 (2007) Shell model: E. Caurieratal. Rev. Mod. Phys. 77, 427 (2005).

Experimental sensitivity T0n1/2 ~ e . a e – efficiency, a – enrichment, M – mass, t - time of measurement (limited), FWHM – energy resolution, B - background

Experimental Technique Two classes of approach to the experiment: Active detector Ionization detectors : HPGe, CZT, LXe IGEX, H-M,Gerda, Majorana, COBRA, EXO, XMASS * Klapdor published positve evidence. Phys. Lett. B 586, 198 (2004) Scintillation detectors : CdWo4, CaF2, CaMoO4 KieV-Florence-CdWO4, CANDLES, SNO++ (LSC) Bolometer detectors : TeO2 CUORICINO, CUORE Bolometer + Scintillator: CaMoO4, CdWO4, ZnSe.. Passive detector Tracking detectors : foil +tracking+scin NEMO, MOON, SuperNEMO

Status of neutrino-less double beta decay searches

AMoRe Some Proposals Gerda COBRA EXO Enriched Xe 76Ge CUORE LNGS Majorana 76Ge USA EXO Enriched Xe Gerda 76Ge LNGS CUORE TeO2 bolometers LNGS COBRA And lots of people are thinking about this. This is by no means a complete list, just some proposals that illustrate the range of technologies and isotopes under study. Of course I’m going to focus on the COBRA experiment today since that is what I work on. Super NEMO Range of isotopes AMoRe

Scintillation Crystals for bb (Calorimeter technique) 300g 116CdWO4 bb search by Kiev group; >0.7x1023 years Enrichment, PSD, active shielding -> successful CaMoO4 ; Mo, Ca bb search * First recognized by this group (H.J.Kim et al, New view in particle physics,Vietnam Aug 2004.) * Scintillation bolometer CaMoO4 DBD for 100Mo (3034 keV), 48Ca (4272 keV) Light output; 10-20% of CsI(Tl) at 20o, increase at lower temp. Decay time ; 16 μ sec Wavelength; 450-650ns-> RbCs PMT or APD Pulse shape discrimination First developed 2003 (5x5x5mm3)

History for CaMoO4 1) 2002 : Idea and try to grow CMO in Korea 2) 2003 : Discussion with V.Kornokov => Send test CMO (better quality) 3) 2004 : CMO test and Conference presentation, Extended idea of XMoO4, low temp. CaMoO4 4) 2005-2007 : Large CMO with 1st ISTC project 5) 2006 : Discussion with F. Danevich => CMO by Lviv and collaborative effort 6) 2007 : CMO R&D in low temp. started. 7) 2008 : 2nd ISTC approved in Russis (3kg 100Mo and 48Ca depleted CaMoO4 crystal growing project) 8) 2009 : AMORE collaboration formed Proc. New View in Particle Physics (VIETNAM ’2004) Aug. 2004, p.449 IEEE Nucl. Sci. 52, 1131 (2005) NIMA 584, 334 (2008) IEEE Nucl. Sci. (2010)

AMoRE Collaboration 4 countries 9 institutions 69 collaborators Korea (35) Seoul National University : H.Bhang, S.Choi, M.J.Kim, S.K.Kim, M.J.Lee, S.S.Myung, S.Olsen, Y. Sato, K.Tanida, S.C.Kim, J.Choi, H.S.Lee, S.J.Lee, J.H.Lee, J.K.Lee, X.Li, J.Li, H.Kang, H.K.Kang, Y.Oh, S.J.Kim, E.H.Kim, K.Tshoo, D.K.Kim(24) Sejong University : Y.D.Kim, E.-J.Jeon, K. Ma, J.I.Lee, W.Kang, J.Hwa (5) Kyungpook national University : H.J.Kim, J.So, Hua Jiang, Y.S.Hwang(4) KRISS : Y.H.Kim, M.K.Lee, H.S.Park, J.H.Kim, J.M.Lee , K.B.Lee(6) Russia (16) ITEP(Institute for Theoretical and Experimental Physics) : V.Kornoukhov, P. Ploz, N.Khanbekov (3) Baksan National Observatory : A.Ganggapshev, A.Gezhaev, V.Gurentsov, V.Kuzminov, V.Kazalov, O.Mineev, S.Panasenko, S.Ratkevich, A.Verensnikova, S.Yakimenko, N.Yershov, K.Efendiev, Y.Gabriljuk (13) Ukraine(11) INR(Institute for Nuclear Research) : F.Danevich, V.Tretyak, V.Kobychev, A.Nikolaiko, D.Poda, R.Boiko, R.Podviianiuk, S.Nagorny, O.Polischuk, V.Kudovbenko, D.Chernyak(11) China(3) Tsinghua University : Y.Li, Q.Yue(2) Sichuan University : J. Zhu(1) 4 countries 9 institutions 69 collaborators

100Mo, 40Ca enriched materials (Prepared by V.N.Kornoukhov) Mo-100 isotope production: The ECP (Electrochemical plant) Zelenogorsk, Krasnoyarsky kray, Siberia 100MoO3 oxide with mass of Mo-100 : 2,5 kg Enrichment: Mo-100 = 96,1% Impurities (the results from ICP MS measurements): U <= 0.00007 ppm (< 0,07 ppb) and <= 0.0002 ppm (< 0,2 ppb) Th <= 0.0001 ppm (< 0,1 ppb) and <= 0.0007 ppm (< 0,7 ppb) 226Ra < 2,3 mBq/kg, 228Ac < 3,8 mBq/kg Current capacity is 0,6 kg of Mo-100 per month (7-8 kg per year). The industrial separator SU20 Lesnoy, Sverdlovky region 27 kg of Ca-40 (40CaCO3) is available now at EKP, Lesnoy Ca-48 < 0,001%

48Ca Enrichment/Depletion at KAERI(Korea Atomic Energy Research Institute) ALSIS (Advanced Laser Stable Isotope Separation) - Features : Isotope-Selective Optical Pumping (ISOP) followed by Non-selective Resonant Photoionization (RPI) - ISOP gives good isotope-selectivity and non-selective RPI high yield. + RPI (-) Charge collector target isotope other isotope target isotope ion Atomic vapor ISOP

48Ca Enrichment/Depletion at KAERI Special features of ALSIS - Isotope-selective optical pumping followed by resonant photo-ionization - Ideal for 48Ca Production - Fiber-based lasers : most advanced, maintenance-free Engineering Demonstration (2010~2012) - Production capability : 1kg/yr Production Demonstration for (2013 – 2014) - Production capability : 5 kg/yr

CaMoO4 crystal development 12.5 cm 2.2 cm Russia(2006) Korea(2003) Ukraine-CARAT(2006) IEEE/TNS 2008 30x30x200mm Russia (2007), 1st ISTC project 2nd ISTC project (2009~) for 48deplCa100MoO4

CaMoO4 crystal Photo-electron yield 4% FWHM at 3 MeV Only with photoelectron statistics

CaMoO4 crystal energy resolution optimization 137Cs 6 oC NIMA 584, 334 (2008) 27 oC 5% FWHM at 3 MeV

CaMoO4 study Ea/b = 0.20 with 5.5MeV a Pulse shape discrimination

BG spectra of SB28 ( by Jungho’s talk) b-a decay in 238U 214Bi (Q-value : 3.27-MeV) → 214Po (Q-value : 7.83-MeV)→ 210Pb a-a decay in 232Th 220Rn (Q-value : 6.41-MeV) → 216Po (Q-value : 6.91-MeV)→ 212Pb Th-232 chain 216Po : 1.61-MeV, 57 events ≈ 0.07mBq/kg U-238 chain 214Po : 1.93-MeV, 63 events ≈ 0.08mBq/kg 220Rn : 1.45-MeV 214Bi (Q-value : 3.27-MeV)

Upgrade plan of 4p CsI detector and shielding cutrrent setup Future setup CsI(Tl) CsI(Tl) CsI(Tl) CsI(Tl) CsI(Tl) CsI(Tl) CsI(Tl) CsI(Tl) 14 CsI channel + 14 PMT 12 CsI channels (side) were shared a PMT with neighbor channel. 14 CsI channel + 26 PMT 12 CsI channels (side) will be attached with 2 PMTs. New Shielding : 10 cm Pb, Polyethylene shielding will be build

Sensitivity of 40Ca100MoO4 Mo-100 2n Signal (mn=0.4eV) Bi-214 Tl-208 3kg (100Mo) : 48Ca depletion 3 years  6.0x1024 y (mn= 0.2~0.7 eV) Mo-100 2n Signal (mn=0.4eV) Bi-214 Tl-208 10s significance Claim by Klapdor-Kleingrothaus et al.  mn = 0.4 eV GEANT4 study (by Dr J.I.Lee)

Low temperature phonon detection technique x-ray, γ-ray, e-, WIMP, etc. Choice of thermometers Thermistors (doped Ge, Si) TES (Transition Edge Sensor) MMC (Metallic Magnetic Calorimeter ) STJ, KID etc.

Scintillating bolometers detection technique Reflecting internal cavity (Ag-coated Cu) Scintillating crystal Ge-NTD Optical detector (Ge disk) 20 mK

Temperature dependence of CaMoO4 SrMoO4 (by Hua Jiang’s talk)

CaMoO4+MMC (By Sangjun’s talk) ~ 500m thick brass base temperature : 13 ~ 100 mK crystal size ~ 1 cm  1 cm  0.7 cm Metallic Magnetic Calorimeter (MMC) Method FWHM = 11.2 keV 241Am a FWHM = 1.7 keV 60keV Astropart. Physi.34, 732, 2011

CaMoO4 DBD Sensitivity 0.5% FWHM 15 keV FWHM Efficiency ~ 0.8 100 kg CaMoO4 Cryogenic detector Mo-100~ 50 kg 0.5% FWHM 15 keV FWHM Efficiency ~ 0.8 5 years, 100 kg 40Ca100MoO4 3 x1026 years ~ 50 meV

Dark matter sensitivity of CaMoO4 cryogenic experiment Bottino et al Trotta et al Ellis et al CaMoO4 CDMS 2008 SuperCDMS 25kg XENON10 2007 XENON100 6000 kgd CMSSM, Ellis et al CMSSM, Markov chain Trotta et al Effective MSSM, Bottino et al Eth=10 keV (5 and 100 kg year) Eth=1 keV by S. Scopel

Thank you